I can place the field in the side, but as far as I can tell there is no way to expand the width of the Document sidebar, so entering and editing text MB fields is difficult. Being able to locate these fields after the Gutenberg title field would be great. But if not possible...
It would be nice to have a MB Block (reusable?) selectable or a separate one for each MB Group/Field one could place in the Block column so you could edit in full width.