Just add an EIP-1271 validator in the signature verification logic loop (if the account has code deployed, call the 1271 validation message)
EIP-4337 compatibility (Involves much larger changes to Delegatable, as the 4337 relay handles multiple things Delegatable does today, including batching).
There are two basic ways:
Related to: https://github.com/delegatable/delegatable-sol/issues/29