It's easy to set mastery level for words and kanji, but I can't figure out how to set the mastery level for grammar points.
I was reviewing a textbook and came across a grammar point I had completely forgot about but saw that it's at 100% mastery here on renshuu 😬. I'd like to reduce the mastery level so that it shows up in quizzes sooner and more frequently rather than wait the long period of time for a 100% mastery item to show up.
You should be able to set the mastery manually by looking up the grammar point in the dictionary and clicking the text that says "Mastery: 100%".
However, manually setting the mastery (on anything, not just grammar) will not affect when you see it next. The date a term is scheduled for review is only set when you answer a question about it; if you change the mastery, you still have to wait for that date before the new level will take effect, unless you set it as Unknown and force it to be re-introduced as a new term.