I suggested in the QoL thread that they add something to the Item Tooltip that says if the item was currently being used in a Gearset (like the overlay icon you see in the armoury list). I think that would help here.

Yea the "Exclud gearset" filter in Grand Co turn-ins is great, and the icon overlay in the armoury list is nice. But there are plenty of other ways to see items (like the DESYNTH window) and the Item Tooltip is the only place where you see the details regardless of context.