Online board for teaching/learning?

Can anyone share a link to an online go board suitable for teaching/learning? Most boards (including OGS Demo Games) have an awkward switch of control in order for two people to show each other move sequences. Looking for something less frustrating and a bit closer to a real board and stones, for teaching/learning.

This is technically possible here on OGS if two users log into the same account. (I had used such a setup for rengo games before rengo was implemented.)

The OGS Terms of Service do not expressly prohibit account sharing for teaching purposes. The Terms only place responsibility for account info and activities with each user: