Why does waypoint radius explode in size when speed > 20 m/s?

Copter is “reaching waypoints” more than a hundred meters in advance of the waypoint when at speeds greater than 20 m/s. I’m assuming this is a safety feature, but it’s beyond exaggerated and causes the copter to cut huge corners which can be dangerous.

This is a known issue, we are working on this: https://github.com/ArduPilot/ardupilot/pull/7659