"you need: VST mixer/device/selected, but to get there you first select: VSTmixer/Selected/selected, and then change the first “selected” into “device”. If you assign a cc and a fader in your controller to that, you can scroll trough the channels (128 max).
Don’t know if this stil works in 8, but you can also ad it manualy:
create a new controller, call it:
SCROLL CHANNEL and select your note/cc and midichannel in the top row
now save (export) the file, and open with notepad. (Save a copy as a backup?)
copy this code into the lower part of the generic remote file, just above the last:
VST Mixer-1selected0
A lot of controllers let you specify different messages on left and right turn… (BCR20000, lemur)
To create buttons that go one channel up or down (endlessly) use: command/navigate/up or down,and assign a cc or note"
and set the generic remote flag to ‘endless’, ‘rotary’ or something like that.