Well, if the room is either blinking or not... why does the number of monsters making/not making them matter?
The RFE clearly stated that monsters would trigger the blinking and it would not be just happening in the background. That would imply that the room would blink according to their movement like it's now doing with the PC's movement. There would be many movements during a single turn.
Why bind it to enemies? If you want it to be permanent, then request it to be permanent.