Is there a multiple selection feature using a checkbox UI?

[hatafull-shimizu]

Issue description:

Hi.
This plugin has helped me a lot. Thanks for the great plugin.

For the most part, the existing functionality is sufficient, but there is one thing I have a problem with.
I want to be able to make multiple selections from a group of items and allow items to be unselected.

I thought Checkbox would solve the problem, but it is the same function as a toggle switch, so it does not meet my requirements.
If I use the multiple option of Select, it appears in the editor as a combo box, so I can make multiple selections.
However, it is not possible to return to the unselected state, so it does not satisfy the requirement completely.

In addition, the combo box is an unusual UI for users who are not familiar with the Web.
They may not notice if it allows multiple selections.

Given the above, I would like to request the ability to select multiple items using a checkbox UI.

Sorry if there is a way to completely meet the requirements with existing functionality. If so, please let me know the procedure.

Best regards.

Lazy Blocks Version:

3.4.2

WordPress Version:

6.2.2

Any helpful information to reproduce the issue (screenshots, code parts)