Stealth is far from dead. I’ve been full time living on the edge of a downtown core in a semi-large city, in a heavily restricted parking area. I’ve never had a knock.
However, if you want to truly be stealth, you need to dedicate the design towards that. That means no swiveling front seats, a solid bulkhead with a door, no windows in the rear, ideally no roof vents or solar, etc.
I keep the cab and exterior of the van clean and bone stock. I drive to my sleeping location right before going to sleep. I never stay in one spot more than 24 hours.
I also disagree that cargo vans are more expensive to convert. You’ll need to tear out the interior of a passenger van to insulate anyways, and I have not seen many full-time conversions that keep much of the stock interior.