I'm one of the people that completed the 100% in 3 days. I previously platinumed the game on PS4 over two months. Unfortunately you can only import saves from PS4 to PS5.
Trophies don't immediately pop, but most will pop when incrementing the value that make them pop or partially fulfilling the requirement again.
For example:
-Completing a mission will unlock the trophy for 500 missions.
- Promoting a miner will pop the trophy for having all miners promoted to gold.
- Collecting a compressed gold chunk, bittergem or alien artifact will unlock their respective trophies.
Some trophies that have specific requirements need to be redone.
For example:
- The trophies for barrels in the drop pod and launch bay need to be redone.
- The Party Time trophy
Some trophy requirements seem to have to be only partially met again.
For example:
- Riding a silicate harvester for any amount of time will unlock the trophy for riding one for 30 seconds.
- Grinding a pipe will unlock the trophy for grinding for 120 seconds.