This is peak table-flavor. Sacrifice your action to smoke and half your Ki comes back? Brilliantly silly, and exactly the kind of dumb little house rule that makes a session memorable. I want this printed on a character sheet as a feat.

That said, it actually has teeth for balance reasons. Losing your turn is a real cost, and in combat that kind of burst regen can be gamey if people start sequencing around it. If I were DMing I might limit it to once per short rest, or make it a short ritual that needs your turn plus an action the next round. Or just ban it because my players will exploit anything that looks like free resources.

Also, 10/10 for naming it Ki-garettes. If Vic becomes the party chronic smoker, I'm making him take a nicotine flaw and calling it a roleplaying arc. Bravo.