Tales of the Valiant, Kobolld Press' 5e reworking; new Luck mechanic

[SouthpawSoldier]

So, I backed Tales of the Valiant; this week saw the release of the SRD, as well as backers receiving their PDFs of the Player's Guide and creature book.

Several classes received changes, Races are now a mix of Lineage and Heritage, Backgrounds are changed; lots of stuff going on.

The main one I wanted to talk about here was the new Luck mechanic, which replaces DM Inspiration Points, and I tell ya folks, I think I'm in love.

All PCs start with 0 Luck. If they miss an Attack or Saving Throw d20 roll (but not Skill Checks) they get 1 point. The DM can also award 1 point for good roleplay, interesting ideas, and so forth, just as they would Inspiration Points. DMs can also award points for succeeding tough combats, completing narrative beats, etc. in addition to XP and GP rewards.

Where Luck differs:

Players can bank up to 5 points; if awarded a 6th, they roll a d4 and that's their new total Luck.

Players spend them differently too. They can spend points for a 1/1 increase of a d20 roll result (e.g. a 12 can be made a 14 by spending two points) OR they can spend 3 points to reroll the d20. Knowing roll success or failure before deciding to spend the points isn't specified, so I could see a PC who rolled OK, but not sure if they met the target value, trying to gamble if a couple points might make the difference.

Oh, and points cannot be spent to turn a roll into a crit success or change a 1 from crit failure; Nat 1 and Nat 20 still emphasize natural rolls.

[J-H]

I've had a few experiences recently where I think this mechanic would have made the play experience better. One is a player running a Fighter who just seems to roll miss/hit, miss/hit, miss/hit.
Another was a Paladin fighting a Balor in a fog cloud. Everyone had disadvantage and there was a ton of missing for like 4 rounds straight.

Has anyone played with this luck mechanic to see how it works? I don't want to introduce it in an already-running game.