I left BunPro for four months.
I don’t think there is a feature to get the hardest grammar points to easiest ones on BP.
I usually use the top left button, then click FINISH or WRAP UP after I answered 1 or 2 questions when I was busy.
I don’t always add lessons.
Oh, I felt I wanted to reset, but I just faced it, anyway, when I came back to BP and got overwhelmed by many reviews. This feeling could differ on each person I think. I don’t remember how many days did I take to zero all my reviews when I came back here.