It does if you make the card self destruct if you don't write "signed, ricardobeat" on it. Courts have been over this in the 1990s with Nintendo. The Gameboy wouldn't boot any game that didn't start with "signed, Nintendo" so game companies just put that there and it wasn't illegal.
(Later, a trick was found to replace the signature and still boot, but it required extra chips in the game cartridge)
That is not the case, is it? You only need to spoof the BambuStudio client in order to use their cloud infrastructure. Sending prints over LAN is still possible without it.
- "It is more convenient" is not a strong enough argument there, that's kind of the point of a commercial venture.
- Yes, they could be nicer about it. They aren't. That doesn't make this any more legal or acceptable.