Currently, it is not possible to multi-select locked elements in a Whiteboard.

This makes locking an element quite destructive as you have to individually select each element you've locked to unlock them.

There is also no way to easily revert the change as there is no History tool to a Whiteboard.

In my case, I've had to spend 1 hour unlocking individual elements after a team member locked the entire whiteboard (not my team member's fault, we love you), not allowing me to do things such as: