#Jocko,
I find the TotalMix Remote Apps kind of hard to handle for less tech savvy artists, even with smaller channel counts.
(1) In my band however the monitor mixes are produced by a Mac computer which mixes the RME inputs (and adds effects, amps, etc, backing tracks), we as artists only get about 5 group channels ('software playback channels as TotalMix calls them) to manage our volumes (in stead of having to handle all input channels). The reroute through the Mac has no noticeable delay for me (bass) and the drummer). You can decide on how many groups you want (20 or 30 would not be a problem, but perhaps defeats the purpose).
In short you use the 'software playback' channels as the monitoring channels for the band members to choose their mix from. Or 'Stems' if you will.
(2) Another approach I can think of is not using the layouts as one for each situation, but as groupers. Kind of as we do at FOH with groups to make fast mixing possible next to 'channel dancing'. So each artist can select the group they want to edit (eg rhythm, vocals, synths, etc) and then set the input channels that show at their input row as they belong to that group.
'I need less of the synths, select the layout 'synths', only those show up. in this case I'd request RME to make more fader groups possible though,as there only for, and lowering all 'synths' takes a 1 fader group and leaves only 3 others.
Hope it helps.
Regards,
Erik