Originally Posted by gengar

I have successfully upgraded using SAUA probably 7-8 times over the last 2-3 years, most recently in September of this year (two months ago). Not once has there ever been I availability, because if there had been I availability I would have booked a straight award ticket (this is also the stated rationale for many other FT'ers, and is the reason we have so many data points on this issue).

Each time, I have called in to BR's Taipei office, confirmed Z availability, and SAUA has been successful.

In case more evidence is necessary, there are many reports from other FT'ers of successful SAUA despite I=0, with many of these FT'ers reporting Z>0. Additionally, as skimthetrees mentions above, at least one FT'er has reported being unable to upgrade when I>0 and Z=0. Here are links to some of these reports: posts [63] [64] [65] [70] [71] [72] [76] [77] in this thread and also post [118] from the UA-specific SAUA thread.