In the quiz.... I don't fell like the questions are focusing on the kanji.. but on the words more . like .. I'd prefer if the question shows only the kanji and we write how to spell it.. or the opposite.. and also.. it'll be much better if we learn the same kanji but with different spellings and words.. this way we'd keep it in mind...and memorize it well.
If you have a kanji schedule, click the three dots and choose the option to create a word helper schedule. This schedule will, according to how you configured it, give you additional words that use the same Kanji, to guarantee that you are using each kanji for multiple words.
If you are following the main word schedules in renshuu, a lot of kanji that only appear in a single word up to the N5 level will repeat at later levels so you'll get multiple words per kanji anyway eventually but a helper schedule can give you those right now if that's your preference.
If you are learning word for something else, nothing is even stopping you from using that word list to create a kanji helper schedule and then using that kanji helper schedule for a word helper schedule so you'll learn all the kanji you use for your current vocab and other words that share the kanji.
You can also adjust which kind of question styles you want from each schedule.
