The red striping on the lace bags looks like it'd be one indicator. The Cactus Jack insignia on the back of fakes seem to be less defined/imprinted. Also, I've noticed the right-angle stitching next to the tip of the big reverse swoosh seems to be closer to the actual swoosh on authentics...
I've always used SNKRS, never used the desktop site on a big release day.
Dumb question but does the purchase button automatically go live at 7am like on the app? Or do you have to refresh?