I use WBEL, and we use yum instead of up2date. It works well for us.
I've just finished reading an interview with Matthew Szulik (in Linux Pro magazine). He's the CEO, Chairman and President of RH, and in the interview he made it clear that RHEL comes with support.
So if there's no documentation on how to set up up2date, and if no one else here can help you, I'd suppose it would be a good question for RH support. (After all, the only real difference between RHEL and WBEL is that with RHEL you get RH support.)
Also, according to the article, RHEL support includes supporting other programs, so that fact that you're using a DA configuration shouldn't matter.
Jeff