At the present state the cabsim on/off affects both at the same time, the monitor out and the power amp out (at the power head).
In our rehearsal room I use a 2x12 cab for the band and a CLR for me simultaneously, which would also be an option for smaller venues without FOH.
I would really like to have the possibility to have cabsim on for my CLR on monitor out and at the same time have it off for the poweramp out into my 2x12.