Does anyone have experience on Coretec Pro Plus XL in Phoenix Oak? I need to make my decision soon. I have a big sample at home to test.

Love the looks (and since I don’t like bevels and this has only microbevels) - but not sure about scratch resistance or the white powder residue.
What’s that all about? I read some others mentioning it looks bad on dark floors and can’t get it off. Phoenix Oak is light and you can’t see it - but if I wipe it with a black cloth (or wear dark clothes) it comes off. I washed the floor sample 3 times and the powder still comes off when wiping.
I want this floor - but not the powdery stuff! I called the flooring store, talked to 5 different Coretec customer reps, and the flooring store Coretec rep. Nobody knows what it is, and say they haven’t heard of it since now. Help!