I generated some subtitles with Aegisub using VSFilterMod and its extra override tags, but found out too late that pretty much no media player supports them (granted I've only tried PotPlayer, VLC, MPV, and MPC-HC).

I'm on PotPlayer and can technically get it working with the following AviSynth script, but the playback gets really slow really fast.
LoadPlugin("C:\Program Files\DAUM\PotPlayer\VSFilterMod64.dll")
The other problem with this script is the sub file has to be external (I plan to mux everything to an MKV) and have to know the file name beforehand.

I honestly don't know what the point of VSFilterMod is when it's so difficult (if even possible) to get working, but again it could just be my naivety.

The biggest "extra" tags I'm using are 1vc, moves3, and moves4. Is there a way to get the same functionality through the baked in tags? Or even better, a way to get the actual filter to work. 😂