I\'m using the final version of Xcode 10 on macOS Mojave beta 11. I downloaded the Additional Tools for Xcode 10 package from Apple\'s website.
When I try to install the
Double clicking the Network Link Conditioner.prefPane in the Additional_Tools_for_Xcode_x.dmg worked for me - it appeared in the Settings after asking for permission to install.
Network Link Conditioner.prefPane
Additional_Tools_for_Xcode_x.dmg