[Jayedog]

I solved the same problem differently, in a way that dsplayer is always using xysubfilter.

I created a media rule to play all file types using lavsplitter, lavvideo, lavaudio, xysubfilter, and ffdshow raw video filter as an "extra filter". You can download that filter from here and then add it to dsplayer in "filters configuration" under filters management.

ffdshow raw filter has an option (and is the only one that I use) to resize your videos while keeping aspect ratio. So, in simple terms, it can "add" black bars, making your video renderer think all your media is, for example, in 16:9. Your movies will look the same but now the subs will have the same size in any scenario.

I know you have everything sorted out, but someone might be interested in this alternative.

Nice this worked good!