Interested in this too. My brake pedal feels "soft" compared to other cars I've owned, and then it has a noticeable initial bite. Not sure when the last (if ever) time the fluid was flushed. I have VCDS but haven't explored this with it yet!
Anotherperson, when you are triggering the ABS and the bleed screw is opened, is someone also pushing down on the pedal?
Relevant info from the link provided by BobnOH:
"If air got into the lines, also bleed the ABS pump, if equipped. Plug in your VCDS diagnostic cable and select module 3 - ABS brakes. Go to Basic settings and select group 1. Hit "Go!" This triggers the ABS pump, during which time you should bleed the system. To build higher pressure than what is possible with a brake bleeder, do the manual "helper pumps the brakes while you bleed method" method. Do this a few times until there's no air in the brake lines and system. This shouldn't take more than 1 minute of running the pump per corner but your situation may vary so consult a professional if you're not sure."
"The advantage of manual pedal bleeding is that it builds much higher pressure in the brake system to push out any old fluid. If you are bleeding the ABS pump I suggest using the manual pedal method with a pressure bleeder to keep the fluid topped off and moving out."
"If you did get an air bubble in the lines while bleeding, you must get it out. If your car is equipped with ABS you must use a VCDS diagnostic cable or equivalent to cycle the ABS pump. After you plug in the cable and start the software, click on ABS pump. Then output tests. Cycle through them and follow the software prompts. This will cycle the ABS pump and it's the only way to get air out of the ABS pump. The service manual doesn't say how long to run the pump so as long as there's no air in the lines, 30 seconds per corner should be sufficient. I don't know the internals of the pump routing so if you bleed the brakes in sequence as before it should completely empty the pump. If air got into the lines, run the pump while bleeding until no more air is in the lines + about another 30 seconds."