I'm not going to run an Ultra past 10k, but at the same time, I suspect it could handle 20k in one of my vehicles, as the driving profile is pretty easy on oil. I'm sure they've done lots of testing and found that in a well maintained engine, they can consistently perform adequately at 20k.
My daughter is running M1 EP and a Fram Ultra in her Renegade. I did that just in case she piles on the miles faster than anticipated and gets lazy with maintenance. I can't imagine her going 20k, but I could certainly see her get to 15k or so before either she or I catches it.