Been There Done That

The completion grind and the trophy most people trip over. You need roughly 90% of all quests - main and side - done, and the catch is that side quests expire: some auto-fail after a few in-game days, and whole batches lock out at the regional points of no return (leaving Trosky when you trigger New Horizons, then the later commit into the endgame). The rule is simple: clear the side content of a region before you push its main quest forward, and don't accept a timed quest you can't finish soon. There's no in-game counter for this, so lean on a checklist walkthrough and mop up each area as you leave it. This is not recoverable once you're past the story gates, so it's the one to plan the whole run around.