mark off the stand by the # of heats you have. say 3 heats, divide it by 3. you must do 1 heat in each 3rd of the stand. much like slot car racing where you must race from each position (and in their case each lane). you could adopt that idea to make it good for all. even the race director could stipulate in the heat postings as to where you need to be for ur round.
just an idea
R