The only thing I think the Mk4 is missing is a camera / octoprint support, but I can live without those.

Firmware 5.1 enabled octoprint support.
Not as far as they’d like, but it works. From memory what is missing is some support when Local and Octoprint mix (i.e. when you print locally, octoprint can’t stop the print. Bit annoying but far from a dealbreaker imho)