One of the most useful things on a surface can be the trim control. When sharing gains between consoles you can’t always rely on gain tracking between them to keep the inputs the same, since you might be recording and that would affect the recording. Having the option of setting the trim as a custom rotary together with the gain and pan would be great
Similarly, but not exactly the same, I’d like to be able to have the preamp section in the upper left be active, but have trim instead of gain on the channel strip rotary encoder.