I think it's unlikely this oil sheared >2 cSt from virgin. Even if Kirkland sheared substantially and had a lot of carryover, oxidative thickening would likely cancel that out by 6,800 miles. Either their WAG of <0.5% fuel is wrong or the KV100 is wrong. Blackstone is notoriously inaccurate on both parameters. I'd have them rerun it.
Results look great for an almost 7k run. I think you've gotten the universal averages from BS so switching to Polaris is a good choice. Does it show how many miles used on the hybrid batteries? Your RX400H Lexus is piling on some miles at 24k in a little over a year.