diff --git a/ax/core/arm.py b/ax/core/arm.py
index af2fc40b924..7389b39b2c3 100644
--- a/ax/core/arm.py
+++ b/ax/core/arm.py
@@ -9,6 +9,7 @@
 import hashlib
 import json
 from collections.abc import Mapping
+from typing import Self
 
 from ax.core.types import TParameterization, TParamValue
 from ax.utils.common.base import SortableBase
@@ -93,7 +94,7 @@ def md5hash(parameters: Mapping[str, TParamValue]) -> str:
         parameters_str = json.dumps(parameters, sort_keys=True)
         return hashlib.md5(parameters_str.encode("utf-8")).hexdigest()
 
-    def clone(self, clear_name: bool = False) -> "Arm":
+    def clone(self, clear_name: bool = False) -> Self:
         """Create a copy of this arm.
 
         Args:
@@ -102,7 +103,7 @@ def clone(self, clear_name: bool = False) -> "Arm":
                 Defaults to False.
         """
         clear_name = clear_name or not self.has_name
-        return Arm(
+        return self.__class__(
             parameters=self.parameters.copy(), name=None if clear_name else self.name
         )
 
diff --git a/ax/core/base_trial.py b/ax/core/base_trial.py
index c06fc2ce7d5..ee201603067 100644
--- a/ax/core/base_trial.py
+++ b/ax/core/base_trial.py
@@ -324,7 +324,7 @@ def update_stop_metadata(self, metadata: dict[str, Any]) -> dict[str, Any]:
         self._stop_metadata.update(metadata)
         return self._stop_metadata
 
-    def run(self) -> BaseTrial:
+    def run(self) -> Self:
         """Deploys the trial according to the behavior on the runner.
 
         The runner returns a `run_metadata` dict containining metadata
@@ -349,7 +349,7 @@ def run(self) -> BaseTrial:
             self.mark_running()
         return self
 
-    def stop(self, new_status: TrialStatus, reason: str | None = None) -> BaseTrial:
+    def stop(self, new_status: TrialStatus, reason: str | None = None) -> Self:
         """Stops the trial according to the behavior on the runner.
 
         The runner returns a `stop_metadata` dict containining metadata
@@ -384,7 +384,7 @@ def stop(self, new_status: TrialStatus, reason: str | None = None) -> BaseTrial:
         self.mark_as(new_status)
         return self
 
-    def complete(self, reason: str | None = None) -> BaseTrial:
+    def complete(self, reason: str | None = None) -> Self:
         """Stops the trial if functionality is defined on runner
             and marks trial completed.
 
@@ -524,7 +524,7 @@ def status_reason(self) -> str | None:
         """Reason string for the trial status (failed, abandoned, or early stopped)."""
         return self._status_reason
 
-    def mark_staged(self, unsafe: bool = False) -> BaseTrial:
+    def mark_staged(self, unsafe: bool = False) -> Self:
         """Mark the trial as being staged for running.
 
         Args:
@@ -542,7 +542,7 @@ def mark_staged(self, unsafe: bool = False) -> BaseTrial:
 
     def mark_running(
         self, no_runner_required: bool = False, unsafe: bool = False
-    ) -> BaseTrial:
+    ) -> Self:
         """Mark trial has started running.
 
         Args:
@@ -572,7 +572,7 @@ def mark_running(
 
     def mark_completed(
         self, unsafe: bool = False, time_completed: str | None = None
-    ) -> BaseTrial:
+    ) -> Self:
         """Mark trial as completed.
 
         Args:
@@ -596,9 +596,7 @@ def mark_completed(
         )
         return self
 
-    def mark_abandoned(
-        self, reason: str | None = None, unsafe: bool = False
-    ) -> BaseTrial:
+    def mark_abandoned(self, reason: str | None = None, unsafe: bool = False) -> Self:
         """Mark trial as abandoned.
 
         NOTE: Arms in abandoned trials are considered to be 'pending points'
@@ -624,7 +622,7 @@ def mark_abandoned(
         self._time_completed = datetime.now()
         return self
 
-    def mark_failed(self, reason: str | None = None, unsafe: bool = False) -> BaseTrial:
+    def mark_failed(self, reason: str | None = None, unsafe: bool = False) -> Self:
         """Mark trial as failed.
 
         Args:
@@ -644,7 +642,7 @@ def mark_failed(self, reason: str | None = None, unsafe: bool = False) -> BaseTr
 
     def mark_early_stopped(
         self, reason: str | None = None, unsafe: bool = False
-    ) -> BaseTrial:
+    ) -> Self:
         """Mark trial as early stopped.
 
         Args:
@@ -670,7 +668,7 @@ def mark_early_stopped(
         self._time_completed = datetime.now()
         return self
 
-    def mark_stale(self, unsafe: bool = False) -> BaseTrial:
+    def mark_stale(self, unsafe: bool = False) -> Self:
         """Mark trial as stale.
 
         Args:
@@ -691,9 +689,7 @@ def mark_stale(self, unsafe: bool = False) -> BaseTrial:
         self._time_completed = datetime.now()
         return self
 
-    def mark_as(
-        self, status: TrialStatus, unsafe: bool = False, **kwargs: Any
-    ) -> BaseTrial:
+    def mark_as(self, status: TrialStatus, unsafe: bool = False, **kwargs: Any) -> Self:
         """Mark trial with a new TrialStatus.
 
         Args:
@@ -724,7 +720,7 @@ def mark_as(
             raise TrialMutationError(f"Cannot mark trial as {status}.")
         return self
 
-    def mark_arm_abandoned(self, arm_name: str, reason: str | None = None) -> BaseTrial:
+    def mark_arm_abandoned(self, arm_name: str, reason: str | None = None) -> Self:
         raise NotImplementedError(
             "Abandoning arms is only supported for `BatchTrial`. "
             "Use `trial.mark_abandoned` if applicable."
diff --git a/ax/core/batch_trial.py b/ax/core/batch_trial.py
index ec51065d45d..f84e8c1ab1e 100644
--- a/ax/core/batch_trial.py
+++ b/ax/core/batch_trial.py
@@ -13,7 +13,7 @@
 from dataclasses import dataclass
 from datetime import datetime
 from logging import Logger
-from typing import Any, TYPE_CHECKING
+from typing import Any, Self, TYPE_CHECKING
 
 import numpy as np
 from ax.core.arm import Arm
@@ -467,9 +467,7 @@ def normalized_arm_weights(
             weights = weights * (total / np.sum(weights))
         return OrderedDict(zip(self.arms, weights))
 
-    def mark_arm_abandoned(
-        self, arm_name: str, reason: str | None = None
-    ) -> BatchTrial:
+    def mark_arm_abandoned(self, arm_name: str, reason: str | None = None) -> Self:
         """Mark a arm abandoned.
 
         Usually done after deployment when one arm causes issues but
diff --git a/ax/core/experiment.py b/ax/core/experiment.py
index 9cdae91e135..071fe83f802 100644
--- a/ax/core/experiment.py
+++ b/ax/core/experiment.py
@@ -15,7 +15,7 @@
 from collections.abc import Hashable, Iterable, Mapping, Sequence
 from datetime import datetime
 from functools import partial, reduce
-from typing import Any, cast, Union
+from typing import Any, cast, Self, Union
 
 import ax.core.observation as observation
 import pandas as pd
@@ -553,7 +553,7 @@ def immutable_search_space_and_opt_config(self) -> bool:
     def tracking_metrics(self) -> list[Metric]:
         return list(self._tracking_metrics.values())
 
-    def add_tracking_metric(self, metric: Metric) -> Experiment:
+    def add_tracking_metric(self, metric: Metric) -> Self:
         """Add a new metric to the experiment.
 
         Args:
@@ -576,7 +576,7 @@ def add_tracking_metric(self, metric: Metric) -> Experiment:
         self._tracking_metrics[metric.name] = metric
         return self
 
-    def add_tracking_metrics(self, metrics: list[Metric]) -> Experiment:
+    def add_tracking_metrics(self, metrics: list[Metric]) -> Self:
         """Add a list of new metrics to the experiment.
 
         If any of the metrics are already defined on the experiment,
@@ -591,7 +591,7 @@ def add_tracking_metrics(self, metrics: list[Metric]) -> Experiment:
             self.add_tracking_metric(metric)
         return self
 
-    def update_tracking_metric(self, metric: Metric) -> Experiment:
+    def update_tracking_metric(self, metric: Metric) -> Self:
         """Redefine a metric that already exists on the experiment.
 
         Args:
@@ -603,7 +603,7 @@ def update_tracking_metric(self, metric: Metric) -> Experiment:
         self._tracking_metrics[metric.name] = metric
         return self
 
-    def remove_tracking_metric(self, metric_name: str) -> Experiment:
+    def remove_tracking_metric(self, metric_name: str) -> Self:
         """Remove a metric that already exists on the experiment.
 
         Args:
diff --git a/ax/core/multi_type_experiment.py b/ax/core/multi_type_experiment.py
index d40884ae93d..b6c552d2bcb 100644
--- a/ax/core/multi_type_experiment.py
+++ b/ax/core/multi_type_experiment.py
@@ -7,7 +7,7 @@
 # pyre-strict
 
 from collections.abc import Iterable, Sequence
-from typing import Any
+from typing import Any, Self
 
 from ax.core.arm import Arm
 from ax.core.base_trial import BaseTrial, TrialStatus
@@ -96,7 +96,7 @@ def __init__(
             default_data_type=default_data_type,
         )
 
-    def add_trial_type(self, trial_type: str, runner: Runner) -> "MultiTypeExperiment":
+    def add_trial_type(self, trial_type: str, runner: Runner) -> Self:
         """Add a new trial_type to be supported by this experiment.
 
         Args:
@@ -122,7 +122,7 @@ def optimization_config(self, optimization_config: OptimizationConfig) -> None:
                 self.default_trial_type
             )
 
-    def update_runner(self, trial_type: str, runner: Runner) -> "MultiTypeExperiment":
+    def update_runner(self, trial_type: str, runner: Runner) -> Self:
         """Update the default runner for an existing trial_type.
 
         Args:
@@ -141,7 +141,7 @@ def add_tracking_metric(
         metric: Metric,
         trial_type: str | None = None,
         canonical_name: str | None = None,
-    ) -> "MultiTypeExperiment":
+    ) -> Self:
         """Add a new metric to the experiment.
 
         Args:
@@ -199,18 +199,26 @@ def add_tracking_metrics(
             )
         return self
 
-    # pyre-fixme[14]: `update_tracking_metric` overrides method defined in
-    #  `Experiment` inconsistently.
     def update_tracking_metric(
-        self, metric: Metric, trial_type: str, canonical_name: str | None = None
-    ) -> "MultiTypeExperiment":
+        self,
+        metric: Metric,
+        trial_type: str | None = None,
+        canonical_name: str | None = None,
+    ) -> Self:
         """Update an existing metric on the experiment.
 
         Args:
             metric: The metric to add.
-            trial_type: The trial type for which this metric is used.
+            trial_type: The trial type for which this metric is used. Defaults to
+                the current trial type of the metric (if set), or the default trial
+                type otherwise.
             canonical_name: The default metric for which this metric is a proxy.
         """
+        # Default to the existing trial type if not specified
+        if trial_type is None:
+            trial_type = self._metric_to_trial_type.get(
+                metric.name, self._default_trial_type
+            )
         oc = self.optimization_config
         oc_metrics = oc.metrics if oc else []
         if metric.name in oc_metrics and trial_type != self._default_trial_type:
@@ -223,13 +231,13 @@ def update_tracking_metric(
             raise ValueError(f"`{trial_type}` is not a supported trial type.")
 
         super().update_tracking_metric(metric)
-        self._metric_to_trial_type[metric.name] = trial_type
+        self._metric_to_trial_type[metric.name] = none_throws(trial_type)
         if canonical_name is not None:
             self._metric_to_canonical_name[metric.name] = canonical_name
         return self
 
     @copy_doc(Experiment.remove_tracking_metric)
-    def remove_tracking_metric(self, metric_name: str) -> "MultiTypeExperiment":
+    def remove_tracking_metric(self, metric_name: str) -> Self:
         if metric_name not in self._tracking_metrics:
             raise ValueError(f"Metric `{metric_name}` doesn't exist on experiment.")
 
diff --git a/ax/core/objective.py b/ax/core/objective.py
index 30b59b8e54b..8036ff57ef8 100644
--- a/ax/core/objective.py
+++ b/ax/core/objective.py
@@ -9,6 +9,7 @@
 from __future__ import annotations
 
 from collections.abc import Iterable
+from typing import Self
 
 from ax.core.metric import Metric
 from ax.exceptions.core import UserInputError
@@ -72,9 +73,9 @@ def metric_signatures(self) -> list[str]:
         """Get a list of objective metric signatures."""
         return [m.signature for m in self.metrics]
 
-    def clone(self) -> Objective:
+    def clone(self) -> Self:
         """Create a copy of the objective."""
-        return Objective(self.metric.clone(), self.minimize)
+        return self.__class__(self.metric.clone(), self.minimize)
 
     def __repr__(self) -> str:
         return 'Objective(metric_name="{}", minimize={})'.format(
@@ -129,9 +130,9 @@ def objectives(self) -> list[Objective]:
         """Get the objectives."""
         return self._objectives
 
-    def clone(self) -> MultiObjective:
+    def clone(self) -> Self:
         """Create a copy of the objective."""
-        return MultiObjective(objectives=[o.clone() for o in self.objectives])
+        return self.__class__(objectives=[o.clone() for o in self.objectives])
 
     def __repr__(self) -> str:
         return f"MultiObjective(objectives={self.objectives})"
@@ -219,9 +220,9 @@ def expression(self) -> str:
 
         return " + ".join(parts).replace(" + -", " - ")
 
-    def clone(self) -> ScalarizedObjective:
+    def clone(self) -> Self:
         """Create a copy of the objective."""
-        return ScalarizedObjective(
+        return self.__class__(
             metrics=[m.clone() for m in self.metrics],
             weights=self.weights.copy(),
             minimize=self.minimize,
diff --git a/ax/core/optimization_config.py b/ax/core/optimization_config.py
index 5e08520aa56..ba5d1138f95 100644
--- a/ax/core/optimization_config.py
+++ b/ax/core/optimization_config.py
@@ -9,6 +9,7 @@
 from __future__ import annotations
 
 from itertools import groupby
+from typing import Self
 
 from ax.core.arm import Arm
 from ax.core.metric import Metric
@@ -80,7 +81,7 @@ def __init__(
         self._outcome_constraints: list[OutcomeConstraint] = constraints
         self.pruning_target_parameterization = pruning_target_parameterization
 
-    def clone(self) -> "OptimizationConfig":
+    def clone(self) -> Self:
         """Make a copy of this optimization config."""
         return self.clone_with_args()
 
@@ -90,7 +91,7 @@ def clone_with_args(
         outcome_constraints: None | (list[OutcomeConstraint]) = _NO_OUTCOME_CONSTRAINTS,
         pruning_target_parameterization: Arm
         | None = _NO_PRUNING_TARGET_PARAMETERIZATION,
-    ) -> "OptimizationConfig":
+    ) -> Self:
         """Make a copy of this optimization config."""
         objective = self.objective.clone() if objective is None else objective
         outcome_constraints = (
@@ -104,7 +105,7 @@ def clone_with_args(
             else pruning_target_parameterization
         )
 
-        return OptimizationConfig(
+        return self.__class__(
             objective=objective,
             outcome_constraints=outcome_constraints,
             pruning_target_parameterization=pruning_target_parameterization,
diff --git a/ax/core/parameter.py b/ax/core/parameter.py
index 7591c525a35..523c7224475 100644
--- a/ax/core/parameter.py
+++ b/ax/core/parameter.py
@@ -14,7 +14,7 @@
 from enum import Enum
 from logging import Logger
 from math import inf
-from typing import Any, cast, Union
+from typing import Any, cast, Self, Union
 from warnings import warn
 
 import numpy as np
@@ -237,7 +237,7 @@ def dependents(self) -> dict[TParamValue, list[str]]:
         )
 
     # pyre-fixme[7]: Expected `Parameter` but got implicit return value of `None`.
-    def clone(self) -> Parameter:
+    def clone(self) -> Self:
         pass
 
     def disable(self, default_value: TParamValue) -> None:
diff --git a/ax/core/runner.py b/ax/core/runner.py
index 0fcf8abff20..39d71ed99f8 100644
--- a/ax/core/runner.py
+++ b/ax/core/runner.py
@@ -10,7 +10,7 @@
 
 from abc import ABC, abstractmethod
 from collections.abc import Iterable
-from typing import Any, TYPE_CHECKING
+from typing import Any, Self, TYPE_CHECKING
 
 from ax.utils.common.base import Base
 from ax.utils.common.serialization import SerializationMixin
@@ -145,7 +145,7 @@ def stop(
             f"{self.__class__.__name__} does not implement a `stop` method."
         )
 
-    def clone(self) -> Runner:
+    def clone(self) -> Self:
         """Create a copy of this Runner."""
         cls = type(self)
         # pyre-ignore[45]: Cannot instantiate abstract class `Runner`.