For manic unicorn members like myself:
A rack counter, visible close to the "new rack" button. Why? It's good to know beforehand if you're about to hit the maximum, and need to delete some of the not super important plans/racks. Especially useful if you plan to add a group of rack plans, say four variations of a single plan (then you can see if there is still room). And to know where your addiction is going... :)
Yes, one could count them manually, but really, in these days???