Should I clear all my Vocab lessons before leveling up?

I’m going to suggest trying my Lesson Filter script instead of the reorder script. While it’s still possible to neglect your vocab lessons if you use it irresponsibly, it’s easier to learn all of the content because it allows you to learn kanji and vocab together. Basically, every time you go to do lessons, you get to pick how many radical, kanji, and vocab items you want to learn. As long as you always do 2-3 times as many vocab as kanji (when available obviously) you’ll never end up with a backlog of vocab items. (This only applies after you clear your current lesson backlog of course.)