My MX 4 will arrive today - I can share if an how I got it running.
Based on this thread Re-assurance request, please - #9 by MSealey my tendency would be to use BetterMouse in combination with BTT to get it to work.
I know that Andreas is working on a native logitech protocol implementation - maybe there are updates!?
Nonetheless, since this mouse is brand new - I would expect a challenge to make it run.