How to lock node editing and begin/end session?

I perceive a use case as follows:
A user with permissions edits a node as normal and locked as normal. But on the edited node there is an option to use B4D. With the node locked, the editor owns the B4D session. Once in the B4D client, an editor can then invite collaborators with read and/or write and/or invite access.
It should not matter if a collaborator walks away from an open session, for the editor owns the B4D session and can end it. The collaborator's work will not be lost because B4D support real-time edits. If an editor is the absent mined own and then the issue of the node being locked is no unique to B4D and treated the same as else where in Drupal.