In reply to Jan Horna.

Yes, there are several ways of hacking together something like that now via CSS and combos of blocks. Of course, there are shortcomings with all of them in comparison to a core standard that binds the data to the Cover block itself.

For your current solution with the Group block, I would recommend using a custom block style. It would let you cut back on all the the nested selectors. Plus, the layout would be reusable, more so if offered as part of a pattern.