Hello,
I think there would be two useful points to add for interactions.
The first being able to select distance from top an element stickies at for prototyping.
β A simple use case for this is floating shopping cart summaries that should sticky below the navigation, not the top edge.
The second is being able to select an element to be sticky to the top of the frame it is in.
β A use case here, simply can be modals or tables that can scroll and need to sticky something afterwards.
Final request would be, an add-on or variant on to the second feature above β being able sticky at top of screen (or distance from top) until the parent frame passes that point, at which point, it scrolls up with its parent frame.