You're not considering the possible impact of the total media area difference between the OG Ultra and the new Ultra, even though the Ascent OG had the 0.7 inch longer size to start with, which in itself could impact the ISO efficiency.
Back when Purolator was Purolator, and wasn't ran by M+H, there was communication with Purolator on the PureONE efficiency - old threads about it still exist in this forum. It was over 99% @ 20μ, similar to the OG Ultra. Yet the PureONE back then was mostly cellulous/blend, never advertised as a "full synthetic" or "dual-layered" media of any kind. The PureONEs back then also had lots of media area. Remember how the increase of dP can impact the ISO test results. We even saw some of that occurring in the Acsent test data. The dP vs debris sloughing factor can really impact the resulting ISO 4548-12 efficiency.