I've created a little app for myself that opens the right (Firefox) profile when another application tries to start the browser. It's registered as the default

I've created a little app for myself that opens the right (Firefox) profile when another application tries to start the browser. It's registered as the default browser so it handles all the cases. I guess I could also write a userscript that handles the links being opened from the browser itself. Like the timewaster extension you mentioned but also starts the right instance in background.