Split render script for VSE? I am looking for an altenative of this script (which split renders a .blend file, much faster): https://github.com/jendabek/BlenderRenderController
but for Linux and working with the latest Blender version. Do you know how I can speed up VSE rendering? I think a bash script can help too (or a python), because there is this api: https://docs.blender.org/manual/en/latest/advanced/command_line/render.html
But somebody must have written this already, I hope. I have 12 cores which I want to utilize.
Use the parallel render add-on: https://github.com/elmopl/ktba/tree/master/scripts/addons

Install it.
Add an absolute path to ffmpeg in the add-on preferences.
Find the Parallel Render options in the Render sidebar.

(For really fast render use AVI JPEG and PR, but you'll have to render audio separate afterwards and mux it yourself)