If you don't like closed source printers, don't look at anything from Anycubic. They all run proprietary FW that you cannot modify on proprietary controller boards, and their hot end also use a custom nozzle thats very close to a volcano but not enough to actually use standard volcano nozzles.
FWIW I have the kobra 2 from them, but it was their last model where you could flash klipper on, and I switched out the hot end for a standard volcano ($35 mod). It's a good printer considering I paid $250, putting out 200mm/s printing and 350mm/s travel with fairly good quality. I have put well over 1000h on mine and aside from bed levelling probe drifting a bit requiring occasional recalibration, it's a solid performer.