I probably should have also said that I am trying to avoid any serious mud work.
Amazingly (to me anyway) I was able to cleanly scrape away the paint in the regions that were bubbling. It doesn't appear they used green/purple board but maybe my house pre-dates that. Also, it doesn't look like they used primer as I was able to scrape down to the drywall surface.
My plan now is to put on a thin coat of mud to seal and transition the scraped edge, put on two coats of a good mold-resistant primer and then paint two top coats. Given the location any minor imperfections should not be very noticeable.
They are all milspec. And milspec has some wobble, unfortunately. That's why people invented those wedges. I think aero lowers have tension screws built in