If an excavator is mining a tile next to a steep cliff and rock continuously falls in, they will continue to mine that area even if the mining area zone has been moved away.
This can trick the user into thinking that there's a lag/delay on the excavtors' queue, not realizing they are just trying to finish that tile before moving on.
A solution could be to have all excavators abandon their current tile if the mining zone is move/edited.
