To supplement the Niai script I recommend using the Item Inspector as an easy way to view visually similar kanji.
You can create different item lists, though I mostly focus on my leeches. When hovering over a kanji, you’ll get a pop-up like this:
It makes it easy to get that overview. I hope this helps!
Good luck with your studies! 
Edit: I missed the fine-print.
The Item Inspector has an export feature also, so you could use that to review items outside of WK.