PRS only uses short leg pickups, as far as I know. They are limited by the shallow cavity depth in the bridge position on trem models which comprise the bulk of their production. That’s why the height screws are shorter for the bridge pickups.
The neck cavities are deeper. The bridge cavity shallower due the bridge spring cavity on the back side. The Core 594, for example, has deeper cavities due to the carved top and no bridge springs. Still, the production of both long and short leg pickups would add unnecessary costs and time to production. It’s simply cheaper and faster to use the same baseplates on all of their pickups.
Is it possible? I guess they may have experimented. That said, I own Cores from 2022 going back to early 2000s and never once seen a long leg PRS pickup. I’ve owned dozens of additional PRS pickups and never seen long legs. The factory videos, even the grainy old ones, that include pickup production have only shown short leg pickups.
Minor variations in leg length likely reflect a change in supplier. PRS doesn’t make any hardware or component parts. All are made to spec by outside manufacturers. They do the winding and assembly of pickups in-house. They do switch suppliers based on pricing and/or volume requirements…PRS dropped Schaller and switched to Gotoh tuners during the Phase 2 era. As I understand it, Schaller had trouble meeting PRS’ quantity and timeliness requireents. PRS is very secretive about its suppliers. Suffice to say, most their component hardware is made in Asia, even for Cores.