I wonder what would happen if they applied an "S" slide to the .45GAP G37/G38/G39. Would it hold up with a Gen4 recoil spring system? In my last Glock AC they told us that slide fractures sidelined G37's with 9mm/.40-width slides. BUT, that was prior to Gen4. Agencies looking to transition from 9mm/.40/.357 to a .45 could use their existing leather gear, but would still have the benefit of a 9mm-sized grip frame.
Of course, the lighter slide would rob the G37/G38/G39 of their soft-shooting characteristcs relative to the .40S&W.
It has possibilities........
Gen1 (G17), Gen2 (G17, G19), Gen3 (G19, G21SF, G26, G39), Gen4 (G19)
Glock Advanced Armorer (AA), Glock Instructor Workshop (IW)
Remington 870, Benelli M1, Smith & Wesson 3000, Mossberg 500