For a duty or defensive weapon I would not recommend it.
The HK45 Compact mag release looks like it drops in, however, when installed on the USP 45 the tab that engages the magazine does not protrude nearly as far into the frame as the stock USP part. Because of the reduced engagement area, some folks have had mags drop under recoil in their USP 45s and 45 Tacticals.
Personally, I wouldn't risk having a mag drop under recoil on a duty weapon. The HK45 Compact mag release definitely FEELS better, but the smaller USP mag release works just fine, while also ensuring the mag stays in the gun.