Do you mean more work on the RD's/SD's by having to declare a race a "Rain Race"?
From a tech inspection standpoint, it is easy. You look at the CC Form, and if the tire is the same size or smaller than on the form, and it is a DOT rain tire, then the points on the form are good. The only issue would be if someone tried to game the system by turning in a new CC Form before the rain race, claiming that was their "new" dry setup (ie. with smaller tires of a lesser point value, using points elsewhere).
The 7-10 points I mentioned above is pretty huge. Yes, a car can dump a huge amount of ballast or add significant bolt-on Aero, and I've seen both.
National TT, PT, & ST Director
Nat. Medical Directorgreg@nasa-tt.com