I have used wide/angle/dh colemak for some time in windows with qwerty virtual keys and finds it working perfectly. I want to do the same in linux i.e. have qwertys ctrl+key behavior but colemak layout.
I often switch between colemak and qwerty so I would prefer to have the physical key mapped so that it don't break qwerty e.g. m:0x4 + c:54 is better than control + c.