Hiding/Exposing feature class attachments to public/secure users

Hello all,

 

 

I have a few feature classes which have attachments turned on in my geodatabase.  Great - users love it.  But Im looking for a way to hide these attached files from public viewers of my Essentials site.  I can always turn off the "Show Relationships by Default" option in Essentials.  But then I cant display these attachments for my secure users.  And the "Add/Remove Relationships" option is grayed out in Essentials for this particular feature class (see pic below).  

 

 

The only workaround I can think of is to bring this service into my site twice (yuk!), one for Public use, and one for secure use.  Im not a big fan of this as it (literally) doubles my administration workload for the same layer(s).  

 

 

Any ideas on this?  Why is the "Add/Remove Relationships" button grayed out?  Has anyone else tried to hide / expose feature class attachments to certain users?