I love this discussion. I'm from Brazil, so sorry for any bad english...
Last year I was playing with some dice probabilities and came up with a mechanic based on PbtA but without the fixed two D6 roll. Every player gets a dice pool, and they use it as a resource, much like the strings from Monsterhearts. So players spend their dice to make a roll, but the results can save them or earn more dice, and that's how the pool is replenished. So if you want to save your pool, or just don't care about that roll, you roll 1 die trying to hit a 6, just to get a mixed result. If you really need to get a high result, you can roll 3 dice so your chances of getting a 10+ result is better.
I created a game (in portuguese) about pirates, actually more about the ship with expendable characters, using that mechanic. The whole dice exchange thing seemed amazing as a meta barter mechanic... so pirates. But it came up overly complex. So last month there was a jam for games in portuguese and I revamped every other aspect of that pirate game but the mechanics, and started writing a space game. But then other work came into the picture and there wasn't enough time to finish it.
Now I'm thinking about revamping it again, adapting it to have a single move mechanic laid out on the character's sheet, no GM (the dice would swap between player's hands the whole game), and keep the space theme and art I did for that almost-to-be game. Sounds fun, and totally doable in this time frame.