Rather than shift clicking while in hand, what about right clicking on the item in the slot to toggle its on/off status? This would be especially useful to quickly toggle curios/baubles equipped without having to remove them.

What about pressing a hotkey when mousing over the item, then?

When I was thinking about the right-click behavior I will admit I was thinking of Quark's feature to swap your equipped armor slot with an equivalent armor piece by mousing over it and right-clicking. It's really handy, but does make sense that kind of behavior is probably from coremodding...

I second this, this would be an incredible QOL adjustment. In fact, being able to do that on any simple toggle-able item while it's in your inventory would be great to turn it off and on, even if it isn't equipped in a Curios slot.

That in my opinion would be very inconsistent with slot behavior as right clicking picks up part or whole stack (if count equals 1). Also that would require core modding at the very least player inventory slots, likely wouldn't be possible to mod other mods slots. So we would end up with something that players would be confused about and sometimes would and sometimes wouldn't work this way.

I believe they got this idea from the cyclic mod. Cyclic does this with their trinkets and handheld power up items/artifacts. You could probably ask to lift the mechanic from them I guess?