Last week I finally got around to putting in the rest of the insulation. I had leftover 4" polyiso foam from the roof. I never though it would be enough, but with a little puzzlework and one new piece of 2'x8' x 2" foam I was able to finish the job.
If I were to do it again, I would make a couple of changes. Because I am using rough cut studs, there is a lot of variance in their dimensions which makes it hard to fit in the pieces of foam. I should have cut everything 3/4" small and filled the gap with spray foam. The way I did it made it hard to fit the nozzle of the foam gun in the cracks. Also, all of the studs were under 4" deep after they dried and some of the foam was as much as 4 1/4" thick, so I had to cut and nail furring strips to the edges of the studs to create an even surface for the blueboard. If I did it again I would just rip the thickness of the foam down on the bandsaw before installing it.