That’s similar to what I came up with, though your superior coding skills have allowed you to do a more thorough job.
Here is my excel sheet of mnemonics - I’ve not shared them before because they are so personalised, but since you asked 
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There’s a combo of fictional characters, famous people and friends & family in there. You may very well be able to guess my age and cultural background if not exactly my country of origin from this stuff!
I have found that they work well enough for some of the later 3+ mora (that’s the actual word for the ‘beats’ you wrote of) words that are not already part of my vocab. Eg. ‘container’ 器 is うつわ, so I picture Uma う Thurman opening a shipping container and being buried in a tsunami つ of belt buckles わ!