Yes…
As an example. Mix 2 (Monitor 2) included in it a guitarist that was too hot in channel 5, also a vocal mic that was too hot in channel 2. It was my understanding that you could press Mix 2 and then adjust channels 2 and 5 using the sliders without selecting them individually. It could be that we were trying to adjust the preamp going into the channel. At any rate, it looked like we had to select a channel before changing it.
A previous comment by LindsaySmith indicated that this is the case for preamp adjustments. Since that is the case selecting each channel would be needed before adjustment but not simply adjusting the balance using the sliders. Sometimes it takes talking things out to understand the situation. Thanks again
