It would be really nice if you could make some items, for example the locksmith keys, compatbile with Curious. We would be able to wear the keys or the key bundle in a Curious slot.

I like this idea 👍. It would save a slot which I definitely think is an improvement.

Next time I have some time I will look into this.

With the latest version 10.0.3 I have added support for both Curios and Trinkets.