I’m totally with you! What I hate even more is when a mnemonic latches onto an English homonym and exploits the wrong meaning 
(most recent example: 扱 means “handle” - the mnemonic latches onto “grip” but the meaning really is more like “to manage”…)
I’m using this script to get a better understanding of what a kanji or vocab means: [Userscript] WaniKani Part-Of-Speech
and I usually add synonyms during lessons already with the [Userscript] WaniKani Lesson User Synonyms v2 script.
Of course the proper way would be to research the vocab in another dictionary, ideally a J-J one, but oftentimes I just can’t be bothered…