I replace all of my USP45 base plates with the smaller factory plates. It helps with concealment "printing".
I often carry my USP45 Expert concealed (including yesterday). I'm 5'-10" x 168pounds with a lean athletic build. No problems with CCW. My gun wears a set of adjustable HK night sights.
I have tried carrying one of my HK45 Tactical and did find the suppressor height sights to be annoying. They "dig into places" and snag on the draw.
The key to carrying something as large as a HK45 or USP45 is belt selection, holster selection and cover garment selection. I use KORE Essential track belts, and custom kydex "wing style" IWB holsters (or Crossbred hybrids). Cover garments can be anything from an untucked polo, untucked oxford, vest, etc. A full size USP45 isn't my first go to in 95-105F summer shorts with t-shirt weather, but it has been done.
ETA: I also replace the base plates on my HK45 Compact with the factory optional flat plates. The finger rest plates look cool, but are useless for carry. My all time favorite 45ACP carry gun is a HK45C. It was a USP45C until I tried the HK45C ... this is coming from a guy that's owned two dozen Wilson, Nighthawk, Les Baer, Ed Brown, etc. HK is the one to rule them all.