Yep. As far as I can tell, some shops won’t fill O2 to service pressure for safety reasons, it seems.
My very limited experience here in the NE with shops is that most of them don't have boosters to accommodate 100% @ 3000psi. So you end up with ~ 70 - 80% or so (100% O2 to whatever they have and then top up with air).
I'm not sure how much more dangerous 3000 is vs 2600.