Your results are not surprising considering your short duration power numbers and leg speed. Typically, roadies start track racing with limited or no fixed gear experience and lack leg speed. You have been riding fixed on the road and working on cadence. Your sweet spot from your track and field days play perfectly with track events coupled with your threshold endurance. You are somewhat of a big fish in a small pond at the moment but that will change as more racers take up track but IMO, you will continue to do well.
I do not do mass start races or match sprints at the track. I do the timed events (500 meters and 2k pursuit), team pursuit and team sprint.