Run scheduled script in multiple browsers (Firefox and Chrome) at same time

I have two scheduled scripts on my Mac to run every morning for some browser RPA work via plist. Is it possible to run these scripts at the same time but on two different browsers (Firefox and Chrome)? Is there any code that I would need to add either to the .html or .scpt files? Any help is appreciated!

(1) Yes, you can run scripts at the same time, either using different browser or with the same browser and different browser profiles.

(2) All works fine with Selenium IDE commands. But XClick and XType control the desktop mouse and keyboard (like a human). So if you use these commands, I recommend to run only only macro at a time (or use virtual machines).

(3) How to do it? See the RPA command line api