Consider supporting TLV 34349334 (basic text message) for keysend payments (like Amboss keysend billboard)

[rolznz]

2024-06-13 08:50:14 INFO  [lightning::ln::channelmanager:6339] Rejecting payment with payment hash 99de4b98ce8d3c7503a254be471bfe8ce802486abfddd5643a57af4302a2aa38 as we cannot accept payment with unknown even TLVs: [34349334]

From tnull:

You'll need to use https://docs.rs/lightning/latest/lightning/ln/channelmanager/struct.ChannelManager.html#method.claim_funds_with_known_custom_tlvs
ChannelManager in lightning::ln::channelmanager - Rust
A lightning node’s channel state machine and payment management logic, which facilitates sending, forwarding, and receiving payments through lightning channels. Instead of claim_fund in your custom TLV implementation.

I think we can maintain a whitelist (just 34349334) and use claim_funds_with_known_custom_tlvs if a TLV matches our whitelist and we understand all the even-numbered TLVs in the payment.