I went through the settings again and discovered some new ones and some good or bad interactions. When I flew into a hangar and extended landing gear, I was still afraid of ramming into a wall due to the remaining momentum. Now I understand how it works: "Automatic slowdown" is what the ship does when landing gear is out. But the problem with this is that it reduces thrust force - generally. But if you turn that nasty "proximity assist" off (which could be useful when maneuvering close to stuff, but is poison for landings), then reverse thrust is no longer gimped but at full force. If you have both settings enabled, then you can hardly brake properly, not even with boost. On my 300i for example, it reduces 3.5 Gs of reverse thrust to 1.0 Gs in proximity and even just 0.6 Gs in landing mode.