Suggestion: Add toggle "Show only known words/kanji" in Vocab Writing

[jVeyZ]

Hi, I've tried using the Writing function for vocab decks and came up with a problem.
While this function does allow you to practice how to write each word, the kanji used for said word in many cases doesn't match the level of the word (i.e. you may be trying to learn how to write the N4 deck but many N3+ kanji you've never seen previously are used for those words). This makes using the Writing function a bit clunky as you are confronted with words you don't even know how to write in kanji form.
I've made a personal script so I can alter the exported savefile and create a brand new Vocab deck that only contains known vocab written with known kanji, and I've found it very useful for practicing as it ties very neatly learning how to write kanji and their general meaning vs where to use them in real worlds.
So I think the app would greatly benefit from adding some sort of option to show you only the words with kanjis you've studied previously. Plus, as the word limit changes dynamically based on new kanji studied it would be a very nice feature to have directly implemented into the app.