I can understand how it might be helpful to be able to mute the channel while still viewing a Mix’s contributions.
and btw wich manufacturer does this with the mute buttons?
Soundcraft’s Expression and Impact consoles have this function, maybe the Vi series does as well, not sure. On the Expression, it’s possible to place a mix on the rotary encoders above each channel by pressing ALT+Mix #; I believe it will stay that way even when you switch layers, but it’s been a while since I’ve had my hands on one.