An unranked to A, S or infinity category for each sport would be nice, although it would be less about speedrunning and more about playing well. It would be easy to reset using the cloud save technique. I know it requires some RNG but not too much because the amount of rank gained/lost before A is always consistent no matter the opponent. A “legend” category could also be added where you speedrun all sports to A rank. Just an idea I came up with!

Edit: the timer would start when the first match (against CPUs) begins and ends when the screen saying “rank up” pops up