Sell it. Yeah, they're unsafe, but tons of things people sell aren't. Has every gun store that's sold an 870 or a 500 told the customer it's not drop safe with a round in the chamber? Has everyone that's sold a non-firing pin block 19/2011 told the receiver that if it's dropped on the muzzle it might fire? How many places sell re manufactured ammo of questionable quality? Or gimmicky nonsense defense ammo like RIP ammo?
I am NOT a 320 defender, far from it- the 320 has problems and really needs to go away. But I wouldn't hold all sellers to some standard. If someone wants to buy a 320, sell it to em. If they ask, tell them many people think the guns has problems and you'd be happy to sell them something else if they're uncomfortable with that. Or disclose it from the beginning.
It's like all the club matches banning 320s- I've watched open guns double at matches, people put rounds into dirt from shadow 2s on load and make ready all the time, handloaded major ammo nukes guns, Serpas still aren't banned from most matches, but social media inertia has made the 320 the gun it's morally ok to ban.