Yep. I did quite a fair bit too, 95% completion. Over-leveled and managed to unlock all DLC skills except 3 upon starting DLC. Disappointed to see there were no power-boosting skills, more like convenience skills. Glad to find out that my excess skillpoints were saved and carried over when I installed the DLC. However I don't think I did it fast cuz my game clock is at 60.5hrs, and others have reported faster playthroughs on PST, but I guess they skipped dialogue. I heard all voiced dialogue and exhausted all dialogue. I particularly liked the holovids and recordings of all the Alpha team members when shit went down. Quite sad actually.
BTW I read there is a "true ending". I dunno if I unlocked the true ending already?
My ending is Aloy visiting the corpse of Elisabet
The first enemy of Frozen Wilds took me by surprised. But I didn't die

the demonic machines are definitely more aggressive, which makes the tripcaster and bombs extra useful now, and the ropecaster not so, seems like demonic machines are more resistant to ropes.