Customize Symbol root element

I'd like to be able to style the root element of a Symbol. For example, if I have a CSS grid, I'd like to be able to specify that a Sidebar Symbol's root element has grid-column: sidebar-start / start-end.

Adding an element within the Symbol and giving it the CSS properties won't work because the Symbol's <div> is actually the child of the grid.

Some ways this could work:

• full style pane customization of the root element (new feature)

• customize just the root element tag (new feature)

• add custom CSS classes on the root element (new feature)

• writing a custom component instead of a Symbol (existing feature, but requires implementation for each client)