I’ve noticed a couple of radicals I don’t exactly love. More specifically, radicals that are never used by themselves and are only ever part of what appears to be a real radical.
For instance, level 31 並 is the “line up” radical. The thing I don’t love about this radical is it’s only used in 普 and 譜, which, unless I’m making some wild assumptions here, use 普 which would always show up as ふ. Maybe those are the only two common kanji that that’s the case for that, but I like to cling to those phonetic radicals for dear life when I find them.
Sounds like you have built some really good knowledge of kanji and how they’re formed
You’re spotting patterns very well and that will help you massively going forward learning Japanese.
Honestly , WK really loses effectiveness in the middle to late 20s. You’ll find a way to move on from WK into just reading native stuff and can self identify kanji you don’t know (and can guess how it’s pronounced too!)
Oddly, in RTK this component (there named “row”) is also used to cover the shape in the bottom right half of kanji like 湿. That gives the primitive more work to do but I think it’s also more confusing…
Sometimes that’s just because later kanji start to have too many radicals in them to make good mnemonics, so they combine some into intermediate radicals. Then the later kanji only have a few, including the new compound radical.