There's a handful of cases when one wants to have a variable that is only used internally. It'd be nice if it'd be possible to natively mark a variable as read-only (for debugging purposes) or hidden completely.
Currently it's possible to set Edit Condition to False for it to be Read Only, and set EditConditionHides to true to hide it, but it's a workaround rather than a BP version of VisibleAnywhereOnly or no such accessor altogether.
A checkbox like Instance Read Only and Hidden for the two features would be ideal from a developer perspective.