How to keyframe a custom property in Qt Design Studio/Qt Quick Designer?

[Shiny]

I have a component with a set of states which basically make a drawer slide open and closed. So it has a "closed" state, a "closing" state which has keyframed animation on the drawer position to slide it closed, an "open" state, and an "opening" state which has keyframed animation on the drawer position to slide it open.

What I want is to animate a custom property value as well which is used in a calculation which changes the color of part of an item in the drawer component. But I see no way to add keyframes to a custom property in the "Properties" editor, or in the timeline, or anywhere else in the Qt Design Studio or Qt Quick Designer UIs.

I tried manually adding keyframes for the custom property in the QML itself, and while that does cause the property to appear in the timeline, with the proper keyframes, it doesn't show a value, and the value doesn't animate when previewed, or show an animated value in the "Properties" editor.

Is it not possible to keyframe-animate a custom property? If it is, what am I doing wrong?

Thanks in advance for any advice.

[Shiny]

So...I though it doesn't show up in the Qt Design Studio/Qt Quick Designer editors in any way, it looks like manually adding the property as a keyframed property, and making sure that it has a defined value in the different states it needs to, it does actually work in preview/at runtime.

Really, then this is more of a feature request: please add keyframe ability to the custom properties editor area...I don't understand how this was overlooked. In fact, why do custom properties not show up in a tab of the "Properties" panel, along with all the other properties of an item/type?