I'm not that afraid of crashes, and I'll have the whole rig on a power conditioner/battery backup.
Sonar isn't really "working" that hard by running two or three plugs at once ... and primarily is acting as an automated midi setup on a per song basis. It's not "running" and trying to play/record.
Conceptually, it's faster (I'm hoping) to have a centralized "library" system rather than having to change things manually between songs on the fly.
All you have to do is have your set list with the individual voicing for each song stored in a project file. Then when opening the project, have the individual keyboards assigned to consistent midi channels (i.e. keyboard one is always on midi channel one etc...), and once the project opens, it automatically sets each individual keyboard to its appropriate settings by loading the voice and assigning the routing.
What I was uncertain of was whether multiple keyboards could be played at once ... or whether you'd only hear the one where the midi channel was highlighted. We're going to have 4 separate keyboards with multiple people playing multiple parts at various times, so the ability to have Sonar play multiple plugs by multiple people inputting at once is critical.
I know that it's going to take some trial and error to figure out exactly how to make things work, but I'm glad to know that if I invest the time doing so, that it is possible.