diff --git a/static/app/views/onboarding/components/scmAlertFrequency.tsx b/static/app/views/onboarding/components/scmAlertFrequency.tsx
index a17e07c47b6704..8f7b04968b02e7 100644
--- a/static/app/views/onboarding/components/scmAlertFrequency.tsx
+++ b/static/app/views/onboarding/components/scmAlertFrequency.tsx
@@ -1,8 +1,9 @@
 import {Input} from '@sentry/scraps/input';
-import {Container, Grid, Stack} from '@sentry/scraps/layout';
+import {Flex, Grid, Stack} from '@sentry/scraps/layout';
 import {Select} from '@sentry/scraps/select';
 import {Text} from '@sentry/scraps/text';
 
+import {IconInfo} from 'sentry/icons/iconInfo';
 import {t} from 'sentry/locale';
 import {ScmAlertOptionCard} from 'sentry/views/onboarding/components/scmAlertOptionCard';
 import {
@@ -31,72 +32,73 @@ export function ScmAlertFrequency({
   const isLaterSelected = alertSetting === RuleAction.CREATE_ALERT_LATER;
 
   return (
-    <Stack gap="xl" role="radiogroup" aria-label={t('Alert frequency')}>
-      <ScmAlertOptionCard
-        label={t('High priority issues')}
-        isSelected={isDefaultSelected}
-        onSelect={() => onFieldChange('alertSetting', RuleAction.DEFAULT_ALERT)}
-      />
+    <Stack gap="lg">
+      <Stack gap="md" role="radiogroup" aria-label={t('Alert frequency')}>
+        <ScmAlertOptionCard
+          label={t('High priority issues')}
+          description={t('Alert on new, regressed, and escalating issues')}
+          isSelected={isDefaultSelected}
+          onSelect={() => onFieldChange('alertSetting', RuleAction.DEFAULT_ALERT)}
+        />
 
-      <ScmAlertOptionCard
-        label={t('Custom')}
-        isSelected={isCustomSelected}
-        onSelect={() => onFieldChange('alertSetting', RuleAction.CUSTOMIZED_ALERTS)}
-      >
-        <Container paddingLeft="2xl">
-          <Stack
-            gap="lg"
-            padding="sm 0 0 2xl"
-            borderLeft={isCustomSelected ? 'accent' : 'secondary'}
-          >
-            <Stack gap="xs">
-              <Container>
+        <ScmAlertOptionCard
+          label={t('Custom threshold')}
+          isSelected={isCustomSelected}
+          onSelect={() => onFieldChange('alertSetting', RuleAction.CUSTOMIZED_ALERTS)}
+        >
+          {isCustomSelected && (
+            <Stack gap="lg">
+              <Stack gap="xs">
                 <Text size="md" density="comfortable">
                   {t('When there are more than')}
                 </Text>
-              </Container>
-              <Grid gap="md" columns=".35fr .65fr">
-                <Input
-                  size="sm"
-                  type="number"
-                  min="0"
-                  placeholder="10"
-                  value={threshold}
-                  onChange={e => onFieldChange('threshold', e.target.value)}
-                  disabled={!isCustomSelected}
-                />
-                <Select
-                  size="sm"
-                  value={metric}
-                  options={METRIC_CHOICES}
-                  onChange={option => onFieldChange('metric', option.value)}
-                  disabled={!isCustomSelected}
-                />
-              </Grid>
-            </Stack>
-            <Stack gap="xs">
-              <Container>
+                <Grid gap="xl" columns={{sm: '1fr', md: '1fr 1fr'}}>
+                  <Input
+                    size="md"
+                    type="number"
+                    min="0"
+                    placeholder="10"
+                    value={threshold}
+                    onChange={e => onFieldChange('threshold', e.target.value)}
+                  />
+                  <Select
+                    size="md"
+                    value={metric}
+                    options={METRIC_CHOICES}
+                    onChange={option => onFieldChange('metric', option.value)}
+                    menuPortalTarget={document.body}
+                  />
+                </Grid>
+              </Stack>
+              <Stack gap="xs">
                 <Text size="md" density="comfortable">
                   {t('a unique error in')}
                 </Text>
-              </Container>
-              <Select
-                size="sm"
-                value={interval}
-                options={INTERVAL_CHOICES}
-                onChange={option => onFieldChange('interval', option.value)}
-                disabled={!isCustomSelected}
-              />
+                <Select
+                  size="md"
+                  value={interval}
+                  options={INTERVAL_CHOICES}
+                  onChange={option => onFieldChange('interval', option.value)}
+                  menuPortalTarget={document.body}
+                />
+              </Stack>
             </Stack>
-          </Stack>
-        </Container>
-      </ScmAlertOptionCard>
+          )}
+        </ScmAlertOptionCard>
+
+        <ScmAlertOptionCard
+          label={t("I'll set up alerts later")}
+          isSelected={isLaterSelected}
+          onSelect={() => onFieldChange('alertSetting', RuleAction.CREATE_ALERT_LATER)}
+        />
+      </Stack>
 
-      <ScmAlertOptionCard
-        label={t("I'll create my own alerts later")}
-        isSelected={isLaterSelected}
-        onSelect={() => onFieldChange('alertSetting', RuleAction.CREATE_ALERT_LATER)}
-      />
+      <Flex gap="sm" align="center">
+        <IconInfo size="md" variant="secondary" />
+        <Text variant="secondary" size="md" density="comfortable">
+          {t('You can always change alerts after project creation')}
+        </Text>
+      </Flex>
     </Stack>
   );
 }
diff --git a/static/app/views/onboarding/components/scmAlertOptionCard.tsx b/static/app/views/onboarding/components/scmAlertOptionCard.tsx
index 6b7e06ce8f9d67..93dd490615bf47 100644
--- a/static/app/views/onboarding/components/scmAlertOptionCard.tsx
+++ b/static/app/views/onboarding/components/scmAlertOptionCard.tsx
@@ -1,8 +1,11 @@
-import {Grid, Stack} from '@sentry/scraps/layout';
+import styled from '@emotion/styled';
+
+import {Container, Flex, Grid, Stack} from '@sentry/scraps/layout';
 import {Radio} from '@sentry/scraps/radio';
 import {Text} from '@sentry/scraps/text';
 
 import {ScmCardButton} from 'sentry/views/onboarding/components/scmCardButton';
+import {ScmCollapsibleReveal} from 'sentry/views/onboarding/components/scmCollapsibleReveal';
 import {ScmSelectableContainer} from 'sentry/views/onboarding/components/scmSelectableContainer';
 
 interface ScmAlertOptionCardProps {
@@ -10,27 +13,70 @@ interface ScmAlertOptionCardProps {
   label: string;
   onSelect: () => void;
   children?: React.ReactNode;
+  description?: string;
 }
 
 export function ScmAlertOptionCard({
   label,
+  description,
   isSelected,
   onSelect,
   children,
 }: ScmAlertOptionCardProps) {
   return (
-    <Stack gap="lg">
-      <ScmCardButton role="radio" aria-checked={isSelected} onClick={onSelect}>
-        <ScmSelectableContainer isSelected={isSelected} padding="lg">
-          <Grid gap="md" align="center" columns="min-content 1fr">
-            <Radio size="sm" readOnly checked={isSelected} tabIndex={-1} />
-            <Text bold={isSelected} size="md" density="comfortable">
-              {label}
-            </Text>
-          </Grid>
-        </ScmSelectableContainer>
-      </ScmCardButton>
-      {children}
-    </Stack>
+    <ScmSelectableContainer isSelected={isSelected}>
+      <Stack gap="0">
+        {/* The padding lives on the button (not the card) so the whole header,
+            edge to edge, is part of the click target. */}
+        <ScmCardButton
+          role="radio"
+          aria-checked={isSelected}
+          onClick={onSelect}
+          style={{width: '100%'}}
+        >
+          <Container padding="lg">
+            <Grid
+              columns="min-content 1fr"
+              gap="0 md"
+              areas={`
+                "radio label"
+                ".     description"
+              `}
+            >
+              <Flex area="radio" align="center">
+                <Radio size="xs" readOnly checked={isSelected} tabIndex={-1} />
+              </Flex>
+              <Container area="label">
+                <Text bold size="sm" density="comfortable">
+                  {label}
+                </Text>
+              </Container>
+              {description && (
+                <Container area="description">
+                  <Text variant="secondary" size="sm" density="comfortable">
+                    {description}
+                  </Text>
+                </Container>
+              )}
+            </Grid>
+          </Container>
+        </ScmCardButton>
+        {/* Selecting the card expands its body; ScmCollapsibleReveal's height
+            tween lets cards in scmCreateProject's layout="position" group
+            reflow smoothly. */}
+        <ScmCollapsibleReveal open={Boolean(children)}>
+          <ExpandedBody>{children}</ExpandedBody>
+        </ScmCollapsibleReveal>
+      </Stack>
+    </ScmSelectableContainer>
   );
 }
+
+// The body indents to line up under the label (header button padding + the xs
+// radio's 12px width + grid column gap) and insets its right/bottom to match
+// the header's padding, since the card itself carries none. The top gap comes
+// from the header button's own bottom padding.
+const ExpandedBody = styled('div')`
+  padding: 0 ${p => p.theme.space.lg} ${p => p.theme.space.lg};
+  padding-left: calc(${p => p.theme.space.lg} + 12px + ${p => p.theme.space.md});
+`;
diff --git a/static/app/views/onboarding/components/scmCollapsibleReveal.tsx b/static/app/views/onboarding/components/scmCollapsibleReveal.tsx
new file mode 100644
index 00000000000000..7fd39af60d3eb5
--- /dev/null
+++ b/static/app/views/onboarding/components/scmCollapsibleReveal.tsx
@@ -0,0 +1,51 @@
+import {useState} from 'react';
+import {AnimatePresence, motion} from 'framer-motion';
+
+interface ScmCollapsibleRevealProps {
+  children: React.ReactNode;
+  /** When true the content is shown; toggling tweens height and opacity. */
+  open: boolean;
+  /** Forwarded to the animated element, e.g. as an aria-controls target. */
+  id?: string;
+}
+
+/**
+ * Reveals or hides content with a height + fade tween. Shared by
+ * ScmCollapsibleSection and ScmAlertOptionCard so their expand/collapse timing
+ * stays in sync. Animating height (rather than display) lets sibling cards in a
+ * framer-motion layout="position" group reflow via normal document flow.
+ * initial={false} renders the open state without animating on mount.
+ */
+export function ScmCollapsibleReveal({open, id, children}: ScmCollapsibleRevealProps) {
+  // overflow:hidden is needed while the height tween runs so the content clips
+  // cleanly, but kept on it would also clip anything that extends past the
+  // settled bounds, e.g. a focus ring at the edge or an open select menu below.
+  // Switch to visible once open and settled, back to hidden whenever animating.
+  const [overflow, setOverflow] = useState<'hidden' | 'visible'>(
+    open ? 'visible' : 'hidden'
+  );
+
+  return (
+    <AnimatePresence initial={false}>
+      {open && (
+        <motion.div
+          key="content"
+          id={id}
+          initial={{height: 0, opacity: 0}}
+          animate={{height: 'auto', opacity: 1}}
+          exit={{height: 0, opacity: 0}}
+          transition={{duration: 0.2, ease: 'easeOut'}}
+          onAnimationStart={() => setOverflow('hidden')}
+          onAnimationComplete={() => {
+            if (open) {
+              setOverflow('visible');
+            }
+          }}
+          style={{overflow, width: '100%'}}
+        >
+          {children}
+        </motion.div>
+      )}
+    </AnimatePresence>
+  );
+}
diff --git a/static/app/views/onboarding/components/scmCollapsibleSection.tsx b/static/app/views/onboarding/components/scmCollapsibleSection.tsx
index 7b8c3acc19b1e7..7bc7d60725aba2 100644
--- a/static/app/views/onboarding/components/scmCollapsibleSection.tsx
+++ b/static/app/views/onboarding/components/scmCollapsibleSection.tsx
@@ -1,12 +1,12 @@
 import {useId, useState} from 'react';
 import styled from '@emotion/styled';
-import {AnimatePresence, motion} from 'framer-motion';
 
 import {Button} from '@sentry/scraps/button';
 import {Flex, Stack} from '@sentry/scraps/layout';
 import {Text} from '@sentry/scraps/text';
 
 import {IconChevron} from 'sentry/icons';
+import {ScmCollapsibleReveal} from 'sentry/views/onboarding/components/scmCollapsibleReveal';
 
 interface ScmCollapsibleSectionProps {
   children: React.ReactNode;
@@ -64,21 +64,9 @@ export function ScmCollapsibleSection({
         </ToggleButton>
         {trailing}
       </Flex>
-      <AnimatePresence initial={false}>
-        {expanded && (
-          <motion.div
-            id={contentId}
-            key="content"
-            initial={{height: 0, opacity: 0}}
-            animate={{height: 'auto', opacity: 1}}
-            exit={{height: 0, opacity: 0}}
-            transition={{duration: 0.2, ease: 'easeOut'}}
-            style={{overflow: 'hidden', width: '100%'}}
-          >
-            <Content width="100%">{children}</Content>
-          </motion.div>
-        )}
-      </AnimatePresence>
+      <ScmCollapsibleReveal open={expanded} id={contentId}>
+        <Content width="100%">{children}</Content>
+      </ScmCollapsibleReveal>
     </Stack>
   );
 }
diff --git a/static/app/views/onboarding/scmProjectDetails.spec.tsx b/static/app/views/onboarding/scmProjectDetails.spec.tsx
index 8a9ab886e2c94d..dbc0420adf53e6 100644
--- a/static/app/views/onboarding/scmProjectDetails.spec.tsx
+++ b/static/app/views/onboarding/scmProjectDetails.spec.tsx
@@ -115,8 +115,14 @@ describe('ScmProjectDetails', () => {
     });
 
     expect(await screen.findByText('High priority issues')).toBeInTheDocument();
-    expect(screen.getByText('Custom')).toBeInTheDocument();
-    expect(screen.getByText("I'll create my own alerts later")).toBeInTheDocument();
+    expect(
+      screen.getByText('Alert on new, regressed, and escalating issues')
+    ).toBeInTheDocument();
+    expect(screen.getByText('Custom threshold')).toBeInTheDocument();
+    expect(screen.getByText("I'll set up alerts later")).toBeInTheDocument();
+    expect(
+      screen.getByText('You can always change alerts after project creation')
+    ).toBeInTheDocument();
   });
 
   it('re-derives the fields when the host clears the form', () => {
diff --git a/static/app/views/projectInstall/scmCreateProject.tsx b/static/app/views/projectInstall/scmCreateProject.tsx
index 77ae0938075bb8..92df68b74825ae 100644
--- a/static/app/views/projectInstall/scmCreateProject.tsx
+++ b/static/app/views/projectInstall/scmCreateProject.tsx
@@ -281,7 +281,7 @@ function ScmCreateProjectWizard({initialState}: {initialState: WizardState}) {
             >
               <Layout.Title>{t('Create a new project')}</Layout.Title>
 
-              <MotionStack paddingBottom="lg" gap="md" layout="position">
+              <MotionStack gap="md" layout="position">
                 <Heading as="h1">{t('Create a project')}</Heading>
                 <Text variant="secondary" density="comfortable">
                   {tct(
diff --git a/tests/acceptance/test_scm_onboarding.py b/tests/acceptance/test_scm_onboarding.py
index 9680c17d866461..395f92887ff91a 100644
--- a/tests/acceptance/test_scm_onboarding.py
+++ b/tests/acceptance/test_scm_onboarding.py
@@ -744,12 +744,10 @@ def test_scm_back_from_setup_docs_active_project_alert_changed(self) -> None:
             self.browser.click('[aria-label="Back"]')
             self.browser.wait_until('[data-test-id="onboarding-step-scm-project-details"]')
 
-            # Switch alerts from "High priority issues" to "create later".
-            self.browser.click(
-                xpath='//button[@role="radio"][contains(., "create my own alerts later")]'
-            )
+            # Switch alerts from "High priority issues" to "set up later".
+            self.browser.click(xpath='//button[@role="radio"][contains(., "set up alerts later")]')
             self.browser.wait_until(
-                xpath='//button[@role="radio"][@aria-checked="true"][contains(., "create my own alerts later")]'
+                xpath='//button[@role="radio"][@aria-checked="true"][contains(., "set up alerts later")]'
             )
             self.browser.wait_until_clickable(xpath='//button[contains(., "Create project")]')
             self.browser.click(xpath='//button[contains(., "Create project")]')