I went through the signup process a month or two ago, but got flat-rejected at the last step (after about half an hour of reading fine print).
The issue: I had temporary hair loss in high school, due to an autoimmune disease according to a dermatologist. I was never tested for it, and figured I could still get tested, but the signup process just stopped me.
I'm in the LA area and willing to drive somewhere to get tested for a match tonight if someone can shed more light on if/how I can do it.