Does CI 4.1.1 fully support running with PHP 8.0.x?

Yes. It runs on PHP 7.3, 7.4, 8.0 +

Thank you sir for your quick response.   Is CI 3.1.11 compliant with PHP 8.0.x as well?  Or do you not have experience with CI 3.1.x?  I am asking these questions to determine whether I will need to first upgrade all of my CI 3.1.x webapps to 4.x prior to our webservers being upgraded from PHP 7.x to 8.x.   Thank you.