Attempting to Have Local and Network User Same Share Local Profile Folder

In the past I have had great success taking a local profile and sharing it
between a local account and a domain account. What I have always done is
go to registry:

HKLM\Software\Microsoft\Windows NT\CurrentVersion\ProfileList

and modify the ProfileImagePath for the new user to point to the existing
user's profile folder.

I then go into File Explorer and make sure that the new user account has
Manager access to the location specified in ProfileImagePath

I did this yesterday on a Windows XP system and something catastrophically
bad is happening. When I login as the new user the desktop is completely
re-arranged. Any changes I make on that desktop are NOT being saved, so if
I log out and login I see the same default condition. I am not able to
change ANY Windows settings for the user.

It looks like there is some restriction in the registry, possibly because
this computer was hardened in the past. What registry entries would I need
to modify so the new user can customize the desktop while logged in and save
those changes?

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W