Use Column labels

I just try this module by creating content and release that labels are not required due to Bootstrap also not providing labels for columns.
And reference module " https://www.drupal.org/project/ckeditor_accordion → " is not using any type of framework like Bootstrap.

labels are not required due to Bootstrap also not providing labels for columns

That's true, maybe they should be configurable?

module ... is not using any type of framework like Bootstrap

I believe this doesn't matter in this case, since I'm proposing an enhancement of editor interface for the grid.

Here's editing experience of Grid vs Accordion:

It's actually makes sense to add styling on editing only view to indicate grid columns (dashed border to indicate columns at least)