The Dollar Sportsman just released his first Zelos videos. His first shots out of the gun (unadjusted/untuned, straight out of the box) were in the 980's for 18.13gr pellets, and he could not get 'reasonable' pellet speeds (880's) until he switched to 25.3's.
I think that he says (maybe in part 2, Slugs) that his reg (from the factory) was received set at ~2,200 psi, even though the book says set it at 1,000-2,000 psi.
His final words - they are coming HOT from the factory (at least his did), so shoot HEAVY projectiles.
Interesting that he was getting basically 1 full mag before needing to re-fill his air (1 mag shot down to ~2,300 psi and his reg was 2,200). At this time he wasn't going to change anything because you wouldn't get all that many more shots by lowering the reg pressure. 20 shots is fine for a hunting gun I guess.