It's working again. Still only for non-ATI machines.
FWIW, with alpha projects, I always select all sub-projects. You can never tell which will be issuing work. Of course, you are taking a risk with any new/alpha project. So go in knowing that you will likely have crunching time wasted or lost, credits could be reset or never exported, or it could even mess with the other sustaining projects you are also crunching. Expect things go wrong, and credit loss.