Thanks, I think that would very likely handle the basic case of having 1 block.

But in a re-usable card component you might decide to have a title, body and footer block where the footer is optional and perhaps falls back with a default value if it's undefined. Slots with Surface handle this use case based on their docs. I think there's a lot of component use cases where you'd want the idea of having multiple blocks.

The docs you linked don't cover if HEEx supports anything like that, or being able to use multiple named blocks in 1 component. I tried to read the source but render_block is a macro and I couldn't proceed to trace it.