^ Thanks for the update. I'm still waiting for my replacement calipers to arrive, but this makes me wonder a) whether the new calipers will have the same issue, in which case I'll just send the replacements back rather than swapping out the currently installed calipers, and b) whether this issue might go away naturally with use. If B is going to happen, I'm kind of hoping for A to happen as well so I can avoid the hassle of a caliper swap (plus writing off a practically new fill of Castrol SRF), although I feel like StopTech would have told me that this would go away with time if that were the case rather than sending replacement calipers. Instead, both StopTech and HP Autowerks said that they'd never heard of this issue.
All that said, if this somehow is a normal deal for the ST60 caliper, obviously I wish they would instead just work out of the box. There's no mention of tight/impossible initial fit on the installation instructions, after all, and a big draw for these calipers is quick and easy pad swaps, which becomes less quick and easy if you need a hammer and pry bar.
But JAJ you're confident that the issue you're seeing WILL go away with time? Or are you just guessing/hoping?