Keeping the SRT as the master next to the video in the repo is the habit that makes the rest easy. Two small additions. Auto captions mangle product names, and button and menu names too, so a short glossary file of UI labels speeds up the hand fix a lot. And since the captions now live in the repo, a renamed button can be caught there: when a release changes a label, search the .srt files for the old word and you'll find every demo whose captions point to something that no longer exists. Rebuilding the .vtt and the burned export from that same corrected master keeps the two from drifting apart.