I don’t know much about this thing. Last time I tried, I got malformed JSON error.
Anyway, there is [For Userscript Authors] WK Queue Manipulator
Nonetheless,
Splice to at most, 10 at once? 5 or less remaining, load the next batch.
Also, so many unused audio files per vocabulary. Maybe disable autoplay altogether, and use the script to preload and play exactly what works. Even for multiple readings, preloading 2 or 3 won’t be too many.