I love the block editor in content template! I'm still learning and confused what is possible. At the moment I'm searching for a way to add a custom image field (or featured image if possible) as a background image for - well, what ever is possible - header, slider, column, simple text, anything. Toolset container doesn't seem to have this feature, I bet other blocks than Toolset don't have it either.
What would be your suggestion to achieve this? A separate view perhaps?