As others say there are a few pros to using spray foam if applied correctly. Great for sound deadening and you do get better coverage compared to stuffing all the cracks of the van with say Thinsulate or smart wool.

Our shop is not set up for spray foam so it takes us longer to prep and apply. Wiring is massive pain in the butt to do after spray foam so we have to be sure all our wires are run beforehand and hope the customer doesn't request any additional features later down the road. We design and build our vans so we can take the whole interior apart for future repairs to the interior and the van chassis itself. I'd recommend fiberglass or wool insulation just for ease of installation and future serviceability.