Post 6,
Thanks for enlightening me on the actual request; and I'm also now more familiar with what SIG has to offer and what the Air Force wants. I was mistaken as to what the USAF wanted after only reading what was provided in Post 1 which indicated the "sub-compact" want. Sorry for my mistake.
I also saw a fellow LEO in my department install a backstrap with the wrong (shorter) pin. Another option for my department could have been to not even give out the extra backstraps w/longer pin; or show the troops ahead of time how to install the backstraps correctly with the longer pin when they issued us the, then new, Gen4s. Maybe the department is doing that now as that was maybe 8 years ago (back in ~2013).