Gee, thanks.
Hadn't considered that.
I've stuffed a camera up both sides on the Axis and there is nothing there other than the radio antenna cable on the driver's side so there's not much that a little moisture would hurt. It's all glass, plastic, and fiberglass.
I'm going to guess ('cause I want it to be true
) that filling the voids will actually reduce air infiltration from the coach and maybe reduce condensation a bit? It may be worth tugging the stuff out and replacing it every couple of years though.
In the Axis the pillars rattle terribly as well as channeling wind and engine noise into the cab. They are only attached on one edge; the other edge is free to clatter and bang against the windshield. Packing the insulation has nearly eliminated that. I really don't want to go back to the din!
Randy