The "spoof" as you call it is literally just using their unmodified code. You make it sound like he went in and deliberately changed it so that it would connect. He did not. That part of the code was left unchanged from Bambu's own publicly available source code.
I agree that they might possibly have a case to go after individual users. They don't have a case to go after this guy for distributing a fork of their software with their own publicly available user-agent string unmodified. Threatening to do so is very much against the spirit if not the letter of the license that they're using.
Using their cloud infrastructure without authorization is different from distributing a fork of their software. They may have a legitimate gripe with the former, but they threatened legal action against the latter. If they didn't want people distributing a fork that could connect to their cloud infrastructure by just using their code verbatim, maybe they shouldn't have designed it that way.
I agree that they might possibly have a case to go after individual users. They don't have a case to go after this guy for distributing a fork of their software with their own publicly available user-agent string unmodified. Threatening to do so is very much against the spirit if not the letter of the license that they're using.
Using their cloud infrastructure without authorization is different from distributing a fork of their software. They may have a legitimate gripe with the former, but they threatened legal action against the latter. If they didn't want people distributing a fork that could connect to their cloud infrastructure by just using their code verbatim, maybe they shouldn't have designed it that way.