Set Seed Glitchless Seed: 10344205394152626 Version: 1.16.3
New world record by Mango here: https://www.youtube.com/watch?v=p9kJ4...
World record because I'm the first player to speedrun this Advancement (as far as I know for java). Other people now ran this and this is still the best time atm. Beds make better chance/rng for it to turn into a villager, even before the lowest 3 min normally. Now I don't know if extra beds (2nd trip) helped because I don't know exactly how the game is coded (no time lost if it isn't).
This seed can be improved in multiple ways: axe to break ladder down to be faster. Pick to break block instead of hand. Better bed locations or 6 iron to craft bars.
For random seed it would just be igloo, and while the zombie is being cured, they gather beds/iron for bars to help speed it up meanwhile.
For no structures: get a zombie village and a witch together so the zombie can be hit with weakness from the witch. Use a tower to spawn/despawn mobs to speed it up.