I have already read the answer about adding aptituted etc. but why not adding skill that reward you by running a specific play style? For end runner you could do something like: "if for the entire race you have been in the back at the start of the last spurt you can move additional tile by consuming stamina (max X tile can be traversed)", same thing for the various lenghts of the tracks, having them as skill would make theme easier to balance too i suppose. Just a thought I had while trying to understand how Speed and Manouvre phase work
Saving stamina early translates to a better last spurt as well as being able to use more skills which help you get ahead. Through our testing we saw that those advantages already do a good job of making up the difference you lost early by not spending stamina so we didn't feel it would do much to include a skill which has a similar effect (falling behind early thanks to not using stamina and then getting ahead at the end thanks to that saved up stamina).
Of course you can always homebrew skills, aptitudes or anything you think would make your games more fun!