Search for tickets without unresolved dependencies

I want to save a search which only returns tickets with 0 active DependsOn linked tickets.

I can easily search for tickets which do or do not have a DependsOn link, but I do not think it is possible to filter on the linked ticket’s status in TicketSQL. (Is it possible to do this another way?)

My next approach was to write a scrip which memos the number of unresolved dependencies for a ticket in a custom field, since custom fields are searchable with TicketSQL. However, I do not want this custom field to be visible to my users (or agents). $ticket->AddCustomFieldValue fails if a field is disabled, and if a field is enabled, it will always appear on the create ticket page no matter what the user’s rights are, even if SeeCustomField, SetInitialCustomField and ModifyCustomField are not granted. (Bug? This is RT 5.0.3.)

What’s the right approach here?

See also: