How to have multiple stretch modes?

Godot emphasized textVersion

4.3 dev5

Question

I’d like to have my UI buttons scale with the same behavior as “canvas_items” but would like my static BG image to have the “disabled” behavior. The result I’m looking for is to never have black borders and anchored UI buttons retaining their scale.

Stretch Mode Disabled
Good: No black borders and BG image fills up entire space
Bad: UI buttons do not scale in size to the viewport.

Stretch Mode Canvas_Items
Good: UI buttons scale to viewport dimensions
Bad: BG Image also scales and leaves black borders.

What I’ve tried
Using a Margin Container with a child HBOX. I would expect the margin container to maintain its margin from the viewport border. However, it does not do this in stretch mode disabled.

Thanks!