Is there is any way for seller to opt out from "Verification" system ?

Just don't provide FBX format, as that is the only file that's checked. I agree it's a deeply flawed system that offers little insight.

It's a shame how cgtrader is throwing at us untested broken features and abandoning them right away. What's the point in such behaviour if it's only making users' experience worse, not better?

Agreed. Verification system should be removed or improved. I offer FBX files, but I don't pack textures into them so that file size remains low, while texture files are a separate file. My models get a low verification score, even saying that textures are missing. Very frustrating as a seller.

I think that verification system is not needed at all! Even without that, it worked just fine, although the idea is not bad, but the implementation is a disaster. Such an unfinished system can only create confusion and potential problems..