Thread drift. I just did my second, three years in. Figured, why worry about scheduling closer to expiration. I'm actually considering renewing my quiz component now too and just getting both done in the same 2-year schedule rather than the maximum 4/2.
I see two advantages. One is, since it's nothing special - we just include it in my annual preventive care checkup - easier to have one date to track. The other is, if I change PCP at some point to someone less "interested," I am always pushing regulatory expiration further out.