For Jumps, it would be more of an issue of controlling when you jump so that you're filling in gaps instead of finishing off your cycle no matter where you are, creating huge wastes, wouldn't it?
Well, certainly you want to use jumps early in the TP cycle to avoid waste -- ideally, within one hit of using a weaponskill. However you also have to account for: different amounts of base TP gain for a jump compared to a normal hit; certain gear boosting the TP return independent of Store TP; and Spirit/Soul jumps doubling/tripling TP return if the wyvern is present.
Essentially, any given jump is unlikely to return exactly the same amount of TP (or 2x/3x for Spirit/Soul) as a standard hit, so it can't strictly be considered a simple replacement for a normal hit in terms of Store TP. That, combined with possible Conserve TP procs, creates a field of values that can shift how many normal melee hits are needed to reach 100 TP, allowing you to drop an extra hit with a small increase in Store TP, or drop Store TP for better melee damage when the Store TP isn't needed. (You could perhaps extend that idea to dropping all Store TP once you pass 100 TP, in case you can't weaponskill at that point for some reason.)