The React BuilderBlock
component always wraps its children in a span or div. However sometimes it might be preferable to have no wrapping element whatsoever. This would make styling of nested components easier and more predictable. And there seems already to be a TODO in your component code:
https://github.com/BuilderIO/builder/blob/40f24ffa48cf602bb6e7e64e0bb967e148124b19/packages/react/src/components/builder-blocks.component.tsx#L97