I would have used expanded foam block insulation, Lord knows I have plenty 3" left over from my in floor heating project I installed when I added on to the machine shop last year (PEX) but rigid foam, while nice, there was not enough room to get free access to the sides. Remember, it's not an open wall, just to access covers.
I sure do like floor heat though. it gets real cold here in the winter and a 65 degree floor is nice on the feet.
Your situation is different than mine is. You primarily camp in campgrounds where you have a pad or graded parking spot so levelling your TC is easier. My wife and I camp primitive all the time and it's rare that where I set down at, that the ground is level. That aspect alone makes a compressor fridge very attractive. If a Dometic compressor fridge works as well as the cool box we now have, it's a winner for us. Camping in the woods or a turnout is a lot different than a campground and why I always have my genny with me.
