For SSSC, it is possible to re-encode the video with subs. Its fixed bitrate, i have the settings written down somewhere, and it does work to hard sub it and then use a tool i wrote to overwrite the original video stream. Problem is youll have some degradation in quality, so ive been holding out to get around to soft subbing it. (Also have a couple of videos still left to be subbed by the translator.)
For audio subs i was trying to re-use the existing text draw routine during audio playback but there are a few bugs. I may just port in some of the text routines i have from lunar 2 instead.
SSS vs. SSSC is the same challenge for subtitles really, just different insertion places in the code.
Dub Audio in SSSC is a challenge because they implemented it differently than in SSS and unless the audio clips are the exact same length as the japanese, there are issues. Needs to be reverse engineered to figure out how to make it happy.