Missed a quest.

[DosDeosos]

So after 3 long hours of play time, I just realized that I forgot to report a quest in Chapter 1 worth of 4 AP. Question is, Am I still getting the achievement or maybe items? or miss it 100% entirely.

[Blood Flowers]

There is a decent buffer for getting S rank AP (which gets you all the AP related items). I think it's like a 10 AP or so buffer. This will still fail to get the achievement for all quests and perfect AP (actually, not sure if perfect AP is an achievement in this one) obviously.

[Entelechia]

It's like around 20s AP of buffer. This game is pretty generous with sidequests this time and there's no MQ hidden behind completing all quests or something so in term of gameplay you should be fine. You won't 100% the student book naturally though (and iirc there's an achievement for that).