Have also never run a return style system, nor see the need for it on a racecar. On a streetcar but not a racecar.

FWIW and my .02 there is NO need to be starting a racecar very often and running it unless it is at the track going to be raced or to possibly check functionality of a major system after a repair, ie converter swap or trans rebuild. Doing this will greatly shorten said motors lifetime. Idling or running them with no load is only going to be detrimental to the motor in the long term.