Well that's an old dusty (even for Festool) thread.
I use the 0 degree base all the time for flushing banding. I modified mine so it has enough capacity for a 3/4" cutter and I found a fantastic down-spiral 8mm bit. It leaves glass.
Can't use the 1.5 degree for that since mating surfaces will show the minimal gap the 1.5 makes. Thinking of shelves in dados.
Since the minimum size I make the banding is 5/8", the Festool bit doesn't work for me.
Here's the posting on my blog about the modification
. In my MFK-700 review video, I mentioned the modification and believe mentioned using a 1/4" down-spiral. Some people tried this modification to the 1.5 degree base and, on that base, the 1/4" won't get all the way down at the furthest reaches. Regardless the base you use, the Vortex Tools 8mm down-spiral referenced in that blog article (which I updated with the Vortex info) will work with room to spare.