First off, the MEF to me is the worst special module of any ship. I generally use it for a hard break expecting incoming fire, like nukes at the first beacon, or when I’m almost dead. At least 75% of the time when it’s because I’m almost dead, I have at least five missiles coming in, and a bunch of people firing at me. They see a ship with less than 25% hull strength and not moving, and fire away so I die the instant the field goes away. I can try a suicide to deny the kill, but the game normally still logs it as a kill for the enemy.
Secondly, the bug. Yesterday I was playing and activated the field. Several enemy ships moved close, like normal, and I died. The killing blow was from an engineering combat drone that was only a couple hundred meters away. It doesn’t look like the combat drones are affected like they should. I would have died anyway, but not by a nearby combat drone.