iPad app should follow channel selection on the console. This way iPad could serve as an additional screen controlling the EQ, Dynamics, etc. for a selected channel.
This is how I use iPad with Yamaha QL and CL series. It’s super useful.
This behaviour should be toggled - some people will still prefer individual control, for example monitor engineers on stage.
The app for the Yamaha LS9, for example, allows the pad to follow the board select, and on a separate switch, for the board to follow the pad; turning the latter off can be handy for using the pad as a low-rent monitor mix surface.