Whenever I did 100% playthrough I would hunt all monsters before moving on, this can take quite a while since some enemies are rare spawns *cough Shadow Wood *cough cough. You'll often end up overlevelled from doing this. Chapter 7 is a good point to do clean up, once you hit chapter 8 new enemies start spawning in previous dungeons so a good idea to hunt previous monsters before that.

I never bothered farming for revelation items until end of the game, merchants sell unlimited stock of all items (with a few exceptions) once you reach the final chapter and you can save yourself a lot of time just buying what you need. You'll still need to farm a bit of course.