RE:
Yes, it works and it looks like the commit history is now up-to-date. Previously it stopped at May 16. I assume because most of the commits are for the Core One L and they didn't want it to leak out before the announcement. In fact it seems that the first Core One L commits where after May which would explain why the history was blocked.
RE: 6.4.0-RC Firmware for Prusa CORE One
Sure but they make it about as easy as it could possibly be for them... MK4S, CORE One, CORE One L, all the same motors, same toolhead, same main board, same lcd, etc.
my XL and MK4S are still on 6.2.6, and the Core one 6.3.4. It'll stay that way until I see better feedback on here. I'm still shaking my head that prusa introduced yet another printer line they have to support.
RE: 6.4.0-RC Firmware for Prusa CORE One
I compiled 6.5.1 myself and installed it. It adds a lot of new settings in the menus! First impressions are that it is noticeably quieter, my wife noticed it without prompting 🙂
I don't know if it's related, but the Z height after homing is a lot higher than before and there now is a "live adjust Z" menu option....
RE: 6.4.0-RC Firmware for Prusa CORE One
Looks like 6.5.1 has just been released: https://github.com/prusa3d/Prusa-Firmware-Buddy/releases/tag/v6.5.1
It is described as "for the Core One L" -- not sure whether it is meant to work on the Core One (and other printers?) as well?