Am I right in assuming that in the classes’ modal, only 7 classes per category are displayed without scrolling?
I think this could be improved dependent on how many rows are displayed.
For example, if everything is displayed in a single row, we should be able to make use of the entire max-height of the modal and not being limited to the class columns’ max-height.
I also think an option to toggle the class hover preview on/off could be something to consider (inside the editor settings).
While toggling between block class and block ID with a single click is a smart and straight-forward implementation, I would like to see the indicator for the ID (always or in case it’s toggled, not sure about it), when the class is currently displayed (and vice versa).