I finally got all the genomes and the bestiary is complete, save for two monsters. One of them I can't get until I get access to the last area. The other one I ended up missing in chapter 4 and before.
I also just moved onto chapter 6. I am disappointed that all the bosses are back again... Took awhile to clear them out a second time in chapter 5, now I gotta do it again...
Do I even get anything like extra updated information, extra party chat scenes or anything special at all for beating them again?
Edit: Apparently I do get updated info and scenes... Welp, on one hand it makes me feel better because I probably would have beat them all again anyways, so the extra stuff is nice. But on the other hand, it's so tedious.
Congrats on completing all that. Yup, in each chapter you will have to beat all the sub bosses again and again in various groupings, and the conversations change. It is all rather exciting really, it gets harder as well. It can be tedious, but I only did not care for the crystal bit over and over again, I did not mind the boss fights. I left my game with everything open as I am really done with it, but I love the music so much in some places and I know I want to just go back and mess around now and then. I hope you enjoy the ending.