Son is fine, it was the coworker friend who does the spray insulation that had the virus. Son helped me spray.
Yes, I already have 3/4 Advantech OSB to go all around the walls.
As far as the R value, I think 1" of foam is supposedly a R-7, but that really isn't an applicable rating for spray foam. Comparing spray foam and batt style insulation via R value is very much like comparing a sports car and a tractor on horsepower. A 60 horsepower tractor will pull plows and implements that a 250 horsepower car wouldn't even move.
The advantage to spray foam, especially in this case the closed-cell foam (which is hard when it cures) is that there is no air penetration at all. Basically I have sprayed my shop with the equivalent of the same insulation in a Yeti cooler.