We anticipate that even with this update, third parties will continue

[XaarKrey]

..which is?

Given the size of this issue, what would you recommend?

One idea: Allow the recipient to reject the gift. They can do so if they already have that mount/minion/emote. This would also give a quick solution if someone got a suspicious gift in the mail they didn't expect (as squeenix claims happens)

The only reason they turned off 1-time items is because someone could be stuck with a duplicate gift they already own.

This would be a significant improvement/addition to the current system.

They could either automatically refund the payment directly when rejected, OR refund the amount spent in crysta to the purchaser to prevent from unnecessary cash flow issues.