To answer my own question, I called and personally spoke with HK Customer Service. I asked specifically about the replacement intervals for my P30L in .40 and VP40;
For the RSA, every 25K rounds (HK Germany's recommendation), every 15K-18K rounds (HK US's recommendation); every 10K-12K rounds if a suppressor is used;
For the Trigger Rebound/Return Spring, every 10K-12K rounds.
Replacement intervals are for live fire roundcounds; I specifically asked about dryfire, and they don't significantly affect spring wear to the point that dryfire manipulations need to be incorporated into the replacement interval count. Good to know.