discussion: planning for insulation in the front/cockpit area of an econoline van

i have plans for the doors, cieling, and pillars, my question is chiefly about the floor/footwell/doghouse area: my going plan is 1/2in xps foam, and 1/4in plywood using my weathertech mat as a template, this would give me an r value of 2 or 3, and would be about as thick as the oem mat. my other idea was to simply lay down thinsulate in the same way the oem insulation is laid down, thinsulate is like 1.6in thick or over twice as thick but i assume it would crush down. thinsulate fully expanded has an r rating of like 5, i’m not sure how badly it being smushed would affect it.

had anyone else here done a custom floor in the front of their van? what did you do for it?