On windows I’m fairly sure one can turn layers on and off while in the middle of a command. On Mac Rhino Version 7 BETA (7.0.20309.06004, 2020-11-04) this is not working — I am able to click the visibility toggle on a layer, but the change doesn’t take effect until after I have finished the command I’m in the middle of.
To reproduce, create a new doc in rhino mac, create a box on layer 1, and while creating a box on layer 2, try turning layer 1 on/off.