I can see both ways here.

If the maintainer just opens the concise bug report they want (RFC .... Section ... If TLS1.3 is negotiated and client sends session id, server must send cipherchangespec), they have what they want and can move on with their life.

However, if the maintainer can get the reporter to do it, the reporter has become a better reporter and the world has become a better place.

IMHO, the original bug report was pretty out there. Asking a library developer to debug a client they don't use with a sever they didn't write either is pretty demanding. I know openssl has a minimal server, I expect woflssl does too? that would be easier to debug.

Actually, on re-reading the original report, the reporter links to a discussion where they have all the RFC references. Had the reporter summarized that to begin with, rather than suggesting a whole lot of other stuff (like a different wolfssl issue that has to be completely unrelated), I think the issue would have gone better.

I will further add that putting a MUST in an appendix seems kind of poor editing. It should have been noted in section 4.1.2 and/or 4.1.3 that a non-empty legacy_session_id indicates that the server MUST send a cipher change spec. It's not totally obvious, but if the client requests middlebox compatability, the RFC says the server MUST do it. If the client doesn't request it by sending a legacy session id, the server can still send a superfluous change cipher spec message if it wants, although I don't know if it will help without the session id.