Hey Chris,
I'm in the same camp as you, and like you, I do a mixture of custom and Adapt programming.
For the majority of our large projects, at least 1 other processor takes responsibility for the other subsystems.
Also, I always use the same program slots for the same subsystems.? (p1=lighting, p2=climate, etc.)
If the client doesn't have one of these subsystems, I just skip that program slot.
With many systems out there like this, I haven't had any issues.? I'm knocking on wood right now!!!
It's so nice to be able to replace a security system (looking at you GE), and the main program never changes or takes a CPU hit.
Brian