Someone correct me if I’m wrong, but I think part of the reason why no one has made a script that can block out certain WaniKani vocabulary items yet is because it’s probably not that easy to make.
IIRC review sessions only have 10 active items at a time (since you only review half of an item at a time, either the reading or meaning, and if you don’t finish both within 2 hours the progress of the item resets) so I imagine that the script would constantly have to check for the blocked item to make sure it doesn’t appear? I think a script made by someone on these forums would have to do it this way, since only WaniKani themselves could remove an item for you client-side, right?