Bambu Studio is open-source and available on GitHub. Prusa complains that it's hard to upstream, yes--but when you look at Prusa's GPL'd firmware for their printers, that's even harder to upstream. They don't even try to upstream to Marlin! But they don't complain about that. At least Creality, of all people, sponsors Marlin development--like, with money.

So what, exactly, is your point here? Bambu is compliant and is reciprocating; OrcaSlicer derives from Bambu Studio and works great. Their printer firmware is not as far as anyone can prove derived from GPL software (and I tend to think that by now somebody would've found it), so they keep that.

Let's get to the brassest of tacks: one can talk about "contributing" until one's blue (or orange) in the face, but Prusa can't or won't ship a functioning, assembled-before-you-get-it multimaterial CoreXY for less than $2,500. Bambu came out the gate with one, not reliant on Marlin or Klipper, and it actually works.

I genuinely can't believe I'm having to point this out, because I think Bambu does suck as a company and sniffing about patents well-and-truly sucks, but they remain, and are the only, such bastard-coated bastards that can actually ship something usable at a price somebody can afford. $2500 for a Prusa XL would be more expensive than my CNC. I actually do need multimaterial, not for models but for tooling, so continuing to limp along with my collection of Klipper printers isn't reasonable. So what's your actual solution for a quality-outcomes tool at a reasonable price?