All is not good in SAUA upgrade land. I almost feel that they have a separate "bucket" for saua's.
Purchased and cancelled two B tickets within the 24hr window. These are just simple tpe-lax rt's. I availability verified via expert flyer and UA. Z availability via customer service.
Z0 I2 = Failed
Z1 I0 = Failed
Z2 I1 = Failed
So I gave up and bought a third ticket on PE and upgraded it using some miles that was going to expire in the next few months. I also asked what fare bucket Saua's are, they gave a canned response =X