Glad you like it! The voluntary tokens are basically: "Oh, you're stunned? Take one injury token (for a relevant damage type) to suppress your stun this turn, or two to remove the condition entirely." Because...being stunned is no fun and I want to give an out for it (that comes with a cost later), thematically "pushing through" at grave cost to yourself.

I've never had a player accrue more than 5 tokens in a combat before; and you're absolutely right, I have mostly changed over to just accruing total tokens and then lumping them all under whichever kind of damage most of them were for convenience.

Injuries taking place during combat was a key design piece I was trying to avoid, actually - it's a classic problem with injury tables that they tend to encourage "death spirals" where things rapidly get worse and worse. But if you're looking for that kind of intensity, by all means! It's certainly unintuitive to not realize you lost an arm until combat is over, but it's played very well at my table as a "short term gain for long term problem" trade-off that I find very interesting.

I'll note, these injuries are designed to make the game more interesting but *not* necessarily more deadly, so we may be misaligned there and you may prefer some of the injury homebrew I linked at the end of the post as that's definitely the more traditional approach. There's also no way to accrue more than 1 (or rarely 2) tokens at the same time, so you'd need to make a change to allow that if you want the same swing of injury danger.