Here is a link to a PowerShell script that will filter an SRT file to only show a small set of fields,
Extract absolute altitude (abs_alt) from DJI SRT files
This is written for PowerShell 7 and tested on Windows with an SRT file supplied by...
I only asked for the OP to send the file to see what the data looked like. I have written scripts to work on transcript files, and while it would be custom, it would be reusable. If you had a folder with 40 srtt files, it would do them all.
Da...
If you have PowerShell installed, you can write a script to edit the SRT file. That script would work on Windows, MacOS, and Linux. If you can PM me and send me a copy of a SRT, I can write the basics of the script.