OK, range update to follow.
Planning to mail the slide out for milling early next week. The real test will be how it shoots with the DP, co-witness, and a comp.
And to be fair, I just compared side-by-side with the HK VP-9 and it also has at least as much vertical play at muzzle end I hadn't noticed before, plus their slide rides over the frame so you don't see the gap. I guess it was handling the threaded barrel end on the P-07 that brought it to my attention.