I like power-ups in races in the sense that they make racing a bit more tactical, while they also add a bit of a surprise element. They are unrealistic in the sense that they don’t exist IRL, but on the other hand Zwift is unrealistic in that there in no wind, crashes etc. Hence, power-ups add an element to racing that is very real, which cannot be accurately simulated in Zwift in any other way at the moment.
However, the handing out of power-ups in races also makes racing a bit too unfair. If you don’t get an aero power-up, you generally don’t stand a chance in the sprint.
I would like to suggest the ability to let racers buy 3-5 power-ups ahead of races. The currency used for the purchase should be earned through training. I guess one could simply use the current XP system, or you could use the TSS from training (although setting inaccurate FTP would make cheating easy). I think this would also be a much greater motivator for racers to earn XPs, than to get a different color of socks etc.