Yes it allows strings or references to the function. My issue is that since the former is allowed, either people start using that method, or you have to start a “debate” within your team about patterns to avoid.

The serializability of your state itself has nothing to do with how events are bound to callback functions. If you serialize a string name of a function and not the source code of that function this buys you nothing. The source code itself is all text, so its serializable no matter whether the code is suitable for being statically analyzed