It's funny, I don't use distortion sense either, but it effectively makes your pickups hotter, which seems like a powerful tool. But I guess I like my pickups sounding how you'd expect them to sound.
But yeah, clean sens is just for balancing dirty and clean within the one rig, not necessarily from rig to rig, that's your rig volume. I never touch rig volume personally, the Kemper does a great job of balancing between rigs itself, as long as your clean sens is set well