We use this script to write to HKCU for all users and default profile for new logins... As you said ActiveSetup is not supported, I would migrate away if possible (we have been for the last year) never know when it will get depreciated.
https://gallery.technet.microsoft.com/scriptcenter/Write-to-HKCU-from-the-3eac1692
With the new add custom files option you can easily add the script, reg files and run pre/post.
https://gallery.technet.microsoft.com/scriptcenter/Write-to-HKCU-from-the-3eac1692
With the new add custom files option you can easily add the script, reg files and run pre/post.