A lot of the issues raised in this post are well solved by commercial video editing software.

For instance, markers and scene detection / edit lists in DaVinci, or word by word editing with recognition in Descript.

I feel like the OP should give them a try before trying to apply the universal script hammer to this problem. The ffmpeg line alone is frightening.

Use of unix time instead of timecode is another problem here.

It’s cool that he wrote this but it doesn’t conform to any video standards in use.