Okay so we can wait for Kent`s response but here is my understanding.
If you look at this link (
VaporShark E-Liquid Testing.pdf - Google Drive you will see that Sugarbear has 1.95 ug/ml of diacetly and 468 ug/ml of AP. Now, I am not sure how AP would translate into Kent`s published analysis. But as far as I know, AP would translate to Pentanedione only, not Acetoin. Somebody can correct me if I am wrong.
In that case, Sure Bert has 10 times diacetly of Sugarbear but still low enough. In terms of pentanedione or AP, Sure Bert actually has at least 450 times less than Sugarbear.
Now, if AP means acetoin + pentanedione, then yeah, Sure Bert has 4 times AP of Sugarbear.
So it is a matter of describing pentanedione and acetoin. As far as I know, AP`s chemical formula is 2,3-Pentanedione so that is why I assumed AP would mean pentanedione in this case.