The normal guidance on applying HKCU changes on a clean install, is to update Default User's NTUSER.DAT with your HKCU edits. This way, every new user account inherits the same settings.
In reality, Windows appears to clobber (or ignore) some HKCU settings when the user account is provisioned at first logon.
The workaround as several IT admins have realized, is to apply the HKCU updates during the first logon session, through a created RunOnceEx task or ordered by FirstLogonCommand in the unattended file.
My command is actually a PS script, since corrective logic has be applied to check if you're on 21H2 vs 22H2-24H2 system.