Like I said before in this thread, I kinda missed the side quests and other stuff to do between chapters, but even in the form game is now, it's fucking long, and I'm surprised they managed to keep it from collapsing, and they managed to keep the main baddies relevant to the story and present in the game even if you didn't see them. The execution difference between this and Pillars of Eternity is huge, in PoE Thaos appears couple of times in the game, and you basically can forget him beside those instances.
I think this is due the structure of the game, you get a game which is very much tied together, but the drawback is that it doesn't lend itself that well for the side content, unless you do it at the expense of the main storyline, or make the game even longer, and as for traditional crpgs like Kingmaker is, rather unique in this regard. Sure there was some side content, but most of it was tied to the either kingdom stuff or the main storyline, at least we weren't put to usually games falls apart about half way through, but Kingmaker IMO didn't suffer from this till the last stretch, but that was due the encounter "design" in HATEOT and the first world after that, rather than the story itself, maybe it was a bit rushed, and the very ending was a bit abrupt that after the fight you get the ending slides, instead of returning to the kingdom yourself with all the allies, would've been nice to see celebrations in the game itself.