No absolutes. It depends on the track, the rider, the event, speeds, etc. For example, a particular front end geometry will work for a particular track curvature at a particular speed. At higher speeds, it's not as good, nor at lower. Some tracks (especially public ones) are made to favor the larger community so they aren't as fast. Those are also more tolerant of different geometries. If you ride something steep and short, you don't just need bottom bracket clearance (though everybody has more than they need for pure clearance issues these days), but the right combination of trail, stem extension, body weight distribution, etc. Basically, you have to be riding on a track, analyze your own position and needs, work with a coach on what someone off the bike sees, and then pick a frame accordingly. If you spend a season in training sessions with other riders at a track, you can ask a lot of questions and participate in a lot of conversations -- you'll get a much better sense of what you uniquely need for yourself. Someone else's solution likely won't work for you. Sorry there isn't a clear answer to your question.