I also digged into this before since I was scripting for some avant-garde faphero that has some really fucked up beat bar. And there’s no music…
This post may be useful for you: Milovana - How to Script a Cock Hero in Under 10 Minutes by LondonGent
If the video beats to the bass then Funscript Generator would be handy. It’s meant to be used with a dedicated beat track, but for most audio you could use the EQ to separate the bass, then let it do the job.
ScriptPlayer.VideoSync by @liquid looks promising as visual-based automation. It’s not released yet and unsupported by the dev atm. I personally have failed to build it after fiddling for days. @LondonGent what is the compiling magic you used there? 
And then I believe Tech_Dave is working on something similar. Good luck with the test flight!