This is purely for what its is worth.
Per Luke B, some years back I bought a box of 45 that I thought was ACP.
Being far removed from the fact that Glock had not only snuck in but made a SHORTER round. Yes, it got loaded, two got fire out of a Star PD (ala Colt Commander from Spain)
Both fired. No damage to gun or person. The Start PD is a lightweight gun.
GAP runs higher pressure, apparently more like +P.
Slightly larger case of 45 ACP would lower that (subject to better info, peak pressure is after a bullet starts moving)
Taking 3/10 of a grain of powder out of the case might be worth considering.
I like the out of the box thinking as long as sufficient research done.