I’ll be checking over the subtitles anyway, generating just saves a bunch of time before a full pass over it. [...] The editing for the subs generation looks to be as much work as just transcribing a handful of frames at a time.

Sorry I'm confused, which is it?

doing this as a favour [...] Honestly I hate the style haha

I'm probably out of line for saying this but I recommend you reconsider.

You may already have the answer from the other comments - but specifically for subtitle transcription, I've used whisper and set it to output directly into SRT, which I could then import directly into kdenlive or VLC or whatever, with timecodes and everything. It seemed accurate enough that the editing of the subs afterwards was almost non-existant.

I can't remember how I installed Whisper in the first place, but I know (from pressing the up arrow in terminal 50 times) that the command I used was:

whisper FILENAME.MP3 --model medium.en --language English --output_format srt

I was surprised/terrified how accurate the output was - and this was a variety of accents from Northern England and rural Scotland. A few minutes of correcting mistakes only.

Yeah, I get that. But seems it's pretty well suited for the task.

You can probably create a similar workflow using comfyui though. But it will require time and effort.

If I pay you to do something I'd expect you to do what I'm paying you to do. If you can't, don't take the job.

I think this libcudnn is a Nvidia CUDA thing. I guess you have checked that the correct CUDA libs are installed and blended has permission and knows where to look for them?

First start for learning blender Python API would be it's documentation: https://docs.blender.org/api/current/index.html

In general you can skip anything that you can do on the user interface. But video editing is just a very small part of this and if you don't have any programming experience yet this could be overkill for what you are looking for.

Perhaps someone had the same problems like you before and implemented something. Maybe searching explicitly for blender video editing automation or Python API will give you some results.