I have MV13's in comms rooms and as you say they used to generate a large amount of alerts when people were working in the comms rooms.
What I have done now is disable motion alerts on these cameras and install an MT20 on the comms room door. That sensor is linked to the MV13.
Now, we only get alerts when the door is opened/closed and the email includes a hyperlink to the camera so you can quickly see who went in if you need to.
This is dramitcally reduced the number of email alerts we were getting.