Only if you’re making changes or trying to measure caster. If you’re just measuring the toe and camber you can do that just parked on a level surface and long as your wheels are straight before you park and you don’t load/unload the car too much. It won’t be perfect but it should be in the ballpark.
Now, you can’t make any adjustments and expect to see those changes reflected accurately unless you roll the wheels or are sitting on turn/slip plates. And you can’t get an accurate caster measurement because that involves turning the wheels.
3/8” toe out is a TON. That will wipe out the inside edge of the tires very quickly.
I run over -1° of camber and don’t see any significant camber wear over the life of my tires. To wipe out the inner edge in 2k miles you’d need a LOT of negative camber, it would be easily visible. Like it would look broken.
If the toe out measurement is accurate that means your toe changed by more than 3/8” somewhere in that 2000 miles. I’d get that thing in the air and make sure nothing is bent, broken or loose before driving it anywhere.