Roomba dock IR

I have an iRobot Roomba dock model 17070. This is what the IR beams are supposed to look like.

Dock IR according to the Open Interface

+ est measurements

But in fact:

• The force field is a circle, but it actually extends 15 inches past the emitter in all directions.
• The buoys are shaped like shown, but are also much larger.
  • Near the dock, they go less than a few inches out.
  • 6 feet or so out they (at least the red buoy) deviate almost a foot and a half out and 5 inches in.
  • At 10 feet, the outward deviation doesn't grow but the inward deviation has, to 7 inches.
  • They go across the room - seriously, I've tested them and they're still readable at 21 feet, although not through the main "omni" receiver.
  • Also, the buoys are transmitted from the pill-shaped carveout on the dock, while the force field is transmitted from the circle on the top.

One more thing: the "left"/"right" receivers don't work in Passive. The Roomba has to be docking or the mode has to be safe or higher.