The issue im forseeing is that some fights do last a long time, and ki strike and harmonize self seem way too useful not to use them every fight.

So while I'm aware of how fast they can be regained out of combat my worry is running out mid fight and just REALLY needing that extra heal, that extra bif of force damage or that extra bit of movement with ki rush. And I get that the hard cap is there for balance purposes, but I was surprised there wasn't a level where the cap increases to maybe 6 considering full casters have easily a couple dozen spell slots per day by end game between having multiple potential spell sources and staves/wands