Blender multiple instances with script


I am trying to create an add-on that separates a list of objects to individual blend files. Kind of like an “export selection to .blend”. Right now I am trying to do so by running a os.system command with the command to run blender with a separate python script that appends and saves the model from the open blend file that I run the script from.

This feels like a very hacky solution and there gotta be a better way. Is there some other way to fire up an instance of blender where I can run an external script that also allows me to report back to the main script how it ran?

Any input is highly welcome!