The only way to use the comp tool in group edit synced tracks is to
a) use the comp tool to make two cuts, then select a different lane (3 clicks)
b) open the lane view of all grouped tracks and sweet (4 clicks)
if using the comp tool in the normal click-hold-drag mode (1 click), only tracks with their lane views open will follow. A lot of potential for things getting very messed up, and the workarounds are quite clunky.