I've been really slowly insulating the rim joist area but thought I'd post a picture or two here on my basement wall idea, and put future updates here. I first strapped 2" of foam to the wall using 1x3's. My idea to put another layer of foam was to mill grooves in more 2" foam boards. I am using a router with a guide on it. A little slow, but could be worse. I've tacked some in place using a hot glue gun. I'll put Densarmor drywall over it.