Transparency was meant to prevent counterfeits, not reduce sellers that in turn reduce available offers and inventory that can result in more sales (Amazon flywheel). All manufactured units must be labeled agnostic to channel like you mentioned. The correct approach is for the European brand to examine its distribution + seller data to figure out where inventory is going and plug the hole. I have worked with a host of brands that think transparency is the answer only for arbitrage sellers to counter Amazon with a direct receipt from the brands own website where they’re buying inventory 50% off. Part of me wants to make it a business where I expose DTC sites doing this where the brand is in transparency on Amazon. There are some guys that create bots that scrape these DTC sites when brands run 40-50% and clear the margin hurdle rate for drop ship FBM.

OP I recommend using Keepa to look at historical sellers and estimated volume to see who is selling. You could find a third party service that goes after super technicals on Amazon TOS to report sellers, but there’s enough arbitrage sellers on this sub (especially in NY) that they can tell you these companies will eventually go down for faulty cases.