I generally use the "Anything I've studied" option for which vocabulary appears in my verb conjugation grammar quizzes, but without further restrictions, it can result in some weird quiz questions. It would be nice if there were ways to limit which of the words studied could appear; in particular, I would like options to exclude user generated words (they often have the wrong verb type listed, which makes the "correct" answer a mystery) and irregular verbs (I'm fine with the standard ones like 行く, 来る, する, etc, but there are some pretty obscure one like あり得る(ありうる) that also appear). Also, it would be cool if verbs that already contain the conjugation being quizzed didn't appear (for example, it makes no sense for compound verbs containing させる to appear in causative quizzes).
I agree completely. It keeps throwing very lengthy expressions during quizzes. Some of which are unquizzable due to weird spacing or already conjugated forms. My quizzes always seem to include already conjugated terms, where the system wants me to conjugate the conjugation.
It doesn't save the setting from quiz to quiz (yet, I'd like to test it out first), but try the new checkbox at the bottom of the quiz settings box to disable user terms, and let me know how it works for you!
So, I haven't had time to test the new feature yet, but I thought I'd mention that the button to close the grammar quiz options had now been pushed off screen in Android: