FYI, Activity Monitor on macOS Mojave and Catalina still doesn't show the URL associated with the process in Activity Monitor with the new RC (using [Version 0.99.127.3.3-rc (WebKit 619.1.11.111.2) / Build date Jun 13 2024]).
If this is a limitation of those versions of the OS (i.e. can't be fixed or can't be fixed without a completely different solution only applicable to those versions of the OS) then understand and please just add a note about minimum OS version required to have this feature.