Since you guys have finished with all of the grammar points that you planned previously from the book I assume you will start working on other grammar that is not part of the books?
In which case here is a convenient list of things that I found in the wild while reading books that you might want to include in BP.
I will keep updating this list as I see more stuff.
Stuff that you definitely need:
- あり (opposite of なし)
- ずく (relying entirely on)
- you have というわけではない but not と言う訳だ
- ~ざる (i.e. ならざる, 見えざる)
Stuff that you might want:
- とけ (short imperative form of ておく)
EDIT (05 Feb 2020) - a few more grammar points you need:
- がん~ (e.g. がん見)
- ~やがる (e.g. しやがる)
- ~振り (e.g. 無茶振り)