I'm playing around with the line of sight behavior to see how it works.
As a test in order to get an idea for how the range would be detected I setup an object inside my game that changes animation when the player is within range using "Has LOS to (player)" and changes back when the player's out of range. I set a 250 pixel range at 10 pixel accuracy.
However... it doesn't seem to actually listen to what you set the range as.
For instance, at 10 pixel accuracy the animation only triggers if you're standing within 10 pixels of the object, even though the range is 250 pixels. If I change the accuracy to 100 pixels, then it will activate within 100 pixels, but not the 250.
I was about to make an example to put up here to demonstrate the problem, but oddly it works fine when you make a new file with it in there... but not in my game itself. No idea why it won't work in my game.