yup.... its there. its works. 12.1

Just add -_GroupTrackFreeze to your options.txt file. Its "experimental" so dont use it in any critical projects, but ive been using it and seems to be working fine. That doesnt mean there isnt any risk.

I have found some plugins dont actually freeze?? the group is frozen, but CPU hit is not reduced.

Hoping this is a step in the right direction, and ableton actually delivers this for us. I know myself, and many others have been asking for years.