Hello,
I just thought I would share some modifications I’ve made to this script for my own personal use, in case someone is interested:
- hiding both japanese and english context sentences (with mouseover reveal)
- hiding the meaning of vocab/kanji/radical when learning them during lessons (mouseover too)
To spare you the wall of text, Pastebin link here: Wanikani hide context sentences updated - Pastebin.com
This is basic and not fully tested, but so far, so good 
Cheers,
Ramul