Bit of a long shot but figured I'd ask to see how viable it might be.

With the release of 2.22 the conditionScript parameter was added as an option for 3DEN Attributes giving you more control over how attributes are shown.

While likely not the intended use, you can use this is to check the value set on another attribute on the same object, however the attribute condition is obviously only evaluated during the loading of the window, as I've demonstrated in the attached video.

Is it viable for a new config parameter to be added to 3den attributes that could somehow allow the condition of attributes to be re-evaluated while the edit window is still open and reveal/hide affected attributes accordingly. I'd envision this only really being done for things like Combo and Listboxes that can make use of onLBSelChanged and would be disabled by default to preserve backwards compatibility. This would be both for regular Cfg3DEN attributes and module specific attributes.