Very few bikes get hammered in the same way a track bike does. Small tracks have high g forces , standing start events put a lot of power through the crank, and short, fast sprint events put a strain on drivetrain parts. Plus, some of the sprint specific track guys are 200 lb guys who squat 400 lbs (or more) and put from 17 or 1800 watts (local fast guys) to 2500 watts (pros) through the cranks
Lots of square taper bottom brackets still being used. For high level usage, the Dura Ace track crank is probably the most popular, but the Sugino 75 and Campagnolo Pista are not far behind, -- The Campy and Sugino products are still square taper
Point being : Upgrade to your hearts desire - we all do it, but just dont kid yourself into thinking any performance gains will be had outside of possible weight reduction