We use Miro-boards in higher education. We may be several teachers developing a board to be used in a course. Locking different parts of a board is almost impossible when several people collaborate.
Securing the setup we make is important. Students working on the boards should not be able to destroy our setup (by accident - or intentionally).
We need a very simple “Glass Layer” to put on top of the board, where the students can work safely without access to the board itself.