I've observed a fair number of our folks bring G27's through qual ranges over the years, and a number of them have used G23/22 mags as their spare mags.
Interestingly enough, I can't remember seeing any of them ever experience a feeding stoppage related to a mag when using their 9rd stock mags, but I can think of a few of them sometimes experiencing feeding stoppages when using G23/22 mags in their 27's. When it happened, being able to fall back on their standard 9rd mags resolved the problems so they could complete the qual courses-of-fire.
While I'd not be surprised that weakening mag springs in the longer 23/22 mag tubes might sooner exhibit feeding issues when being run in the faster cycling, lighter slide mass G27's, not all of the longer mags being used were "old" when it came to mag spring life.
I remember one of the guys who experienced feeding issues when using a G23 mag (w/sleeve) telling me that his G23 "primary" mag was only 3 years old, and he only fired his G27 quarterly (he was authorized to carry his G27 as a "primary" weapon in specialty unit). His standard 9rd mags, which were actually older, fed/functioned just fine in his G27 (and luckily he carried them as spares). Well, to be fair, I've known of the occasional mag spring (and not just for Glock) that "tired" or weakened sooner than might normally be expected, but they're easy to replace if they become symptomatic.
Bottom line? Anything carried for duty/personal use needs to be inspected for normal good condition and checked/used to confirm proper function periodically.
I've not had an urge to use 23/22 mags in my own G27 since I bought it and have been using it since '04. I have, however, commonly used larger mags in my issued 6906 9mm's (meaning 15rd mags as spares instead of the standard 12rd mags), and the next larger single stack mags for my 9/.45's (8rd in a 7rd 9mm; 8rd in a 7rd .45; and 7rd in a 6rd .45). I always did a lot of test-fire and range training/qual function confirmation, though, since my life depended on them functioning.
I've never cared whether guys & gals used longer mags in their small pistols which were originally designed for larger pistols, since those decisions have typically been made above my pay grade. I just rolled with whatever policies were in effect at any given time (although I was asked for my input as an instructor and armorer, from time to time).