Feature request: Allow setting a custom design-mode cover frame for animations

Feature request
I would like the ability to choose which point in an animation is displayed as its static preview in Design mode.

Currently, an animated frame always shows its initial state. This is not always the most representative or useful visual state when working on a layout. My workaround is to create a component with separate “Cover” and “Animation” variants, but this adds complexity and can affect video playback and animation timing.

Ideally, an animation could have a configurable Design mode cover or poster frame. Designers could select a timestamp or capture the current animation state, while playback in Present mode would still begin from the actual start.

This would:

Make animated designs easier to understand on the canvas
Provide more representative thumbnails and previews
Remove the need for duplicate cover variants
Preserve the original animation timeline and video playback
Improve collaboration when reviewing files in Design mode
This could work similarly to selecting a poster frame for a video, but for an entire animated frame or component.