Perhaps I should rephrase the 'known fault' with a 'known issue'. This front brake issue has been covered on ADV as well as other forums. The first I read of it I felt it must be a one off. I then read more and more of the owner reports stating the same symptons and then it clicked, I too had experienced the same issue. I was then able to induce the failing front brake at will. It is something that would only happen at very slow speed. A quick dab on the front brake would render the brake ineffective as the ABS would take over and start pulsating.
I didn't initially tie this experience in with the reports I was reading until it happened a second time. After that, and as I stated above, I could induce it at will at low speed.
The answer - don't try to brake too sharply at slow speed. But then not all riding circumstances are the same from day to day. I've never had this problem before on a conventional braking system, except when I boiled the front brake fluid going down the Stelvio

on a Funduro, two up and loaded, and cannot induce it on the 1200 either, or any other ABS fitted bike I've ridden. That tells me it is not rider error but a design issue.