Aaaaaand finished. Some final thoughts:
Played on tactician mode, didn't see any difference between base DOS and this supposed EE hard mode. In fact, it consistently felt like it was significantly easier all throughout the game.
As for the endgame it's... not very much improved to the honest. You get less "big" choices to do (you can no longer kill Arhu for the lich queen which is a bummer, you can't kill Leandra for good and forget about reforging the soul forge). The sauce temple exterior instead of being full of immaculates and deff knights is now just filled with buttons to push, which is pretty bleh - the interior doesn't seem changed at all, but then again, I skipped it completely and just went for the candle lighting to get the hell out of there asap. After that you go through a few LSD bizarro visions that I don't think really add much and engage in a few pointless fights: First the Trife who sucks a lot and summons some sucky "evil" versions of various NPCs. Next is Leandra and a bunch of daemons with IDDQD that only lose that IDDQD one after another, so it's pretty boring (+ you have Icara and Zandalor support which makes it trivial). Then you get an anti-death knight wang and suddenly have to face 6 of them, which ends in two turns because you instagib them all, no point to that fight at all really. And finally there's the void dragon which got nerfed to hell and back - it has barely 3.5k hp, can't instagib your party members for shit, and you also get Zandalor support on top. Pretty disappointing after the hellish fight that it was in the original.
I also mentioned that before, but I think the EE is also considerably more unstable than the base game, at least in multiplayer. Had a bunch of corrupt saves, my coop partner kept getting connection timeouts and couldn't rejoin frequently, stat-resetting errors that needed reloading also happened basically each time we fired up the game, and some more shit.
Also, this time I paid a little bit more attention to the story, and I dunno if it was re-written for the EE as well, but it made even less sense to me than base. The two guardians were originally generals... who fled the void dragon and the day had to be saved by a 3rd general who sacrificed herself. But somehow the gods thought the two coward generals would make for excellent guardians for the godbox containing the void. And so they were made guardians, got fooled by Astarte and... fled the dragon again when it was unleashed. Then they went through the most impressive surveillance footage wiping in history and erased themselves from time itself so that nobody knew it was their incompetence that doomed the world. Good job, best guardians. At one point we started joking that this story was basically the three two stooges: divinity edition. It was made even better when our final turn against the void dragon was one character flipping on ice, the other launching a blind grenade that only blinded Astarte and none of the 4 void enemies around her, and then finally the dragon suiciding by attacking Madora and getting killed by a 50-hp damage reflection from her armour. Best guardians, best goddess, best dragon. Madora once again saves the day by herself.