Of course it would be nice. If the implementation doesn't crush your gateway hardware.
The fundamental difference between the configuration bindings in UDT members and the bindings in expression tags and query tags, is that the latter subscribe to changes in the tags they reference, when in event driven mode, so they can re-execute to stay up to date.
General tag configuration bindings only execute at tag startup or restart, which is triggered by UDT parameter writes. Alarm configuration properties are more tolerant, because they have to execute when an alarm triggers in order to capture associated data.
Making general tag configuration property bindings subscribe to their references would cause the internal bookkeeping of the tag subsystem to explode. And worse, eventually, because that flexibility would be abused.
What I'm hoping for is some middle ground, limited expansion, whatever, that could be implemented by IA without risking catastrophe.