Moment was still being used in some classes so found and replaced all those instances with Carbon and uninstalled the packaged from composer.
So, @PSR12 is the recommended coding standard, so I updated the config and reformatted the appropriate files. Again. Whew.
I needed some consistent php formatting, so I plugged in a php fixer config and then reformatted all PHP files so it's all consistent. Fixed an ID issue with the page-edit template that was causing page editing to fail.