Got the bottoms of the last three pieces of window pillar trim attached. For one I had to pull the oven temporarily, and the others behind the sink I was able to get one screw in at an odd angle. Finally realized I didn't care since it will be hidden by the removable backsplash anyway.
This let me finish the last three inserts.
Tested out the insulated inserts last night by sleeping in the bus. It got down to 25°F overnight, but my 1500 watt electric space heater kept it at 65°F inside.
Sadly, I realized that the inserts behind the removable backsplashes can't be put in or taken out without removing the backsplashes first. I had thought I could pull the pins out of the hinges and do it, but the bottom hinge still sticks up about 1/4" inch and prevents the top part from coming out. And even if I unscrew the bottom hinge, most of the top ones are still too tight to come straight out. Oh well, the best laid plans ...
I also tested out the acoustic properties of the insulation with my external PC speakers and subwoofer. With the volume fully cranked on my favorite speaker-testing song:
I went outside to see how loud it was. Standing right next to the bus you could faintly hear the music, but 25-30 feet away you couldn't hear anything at all. Sleeping in the bus was also as quiet a night as I've had in a long time, couldn't hear cars driving by like I normally do.