I don't know where your problem with confirmation come from but I always try to avoid using Bitcoin when I exchange my GOLD on Gold marketplace. Indeed, I choose Ethereum to exchange GOLD to ETH, then if I still want to own Bitcoin rather than Ethereum, I will send those Ethereum to get bitcoin back. It takes one more step to do compares to simply exchange GOLD to bitcoin.
The advantage is saving fees and waiting time to get enough confirmations.
My problem basically lies in the lack of experience with Ethereum under stress conditions. As Bitcoin network is getting crowded (now and then, I know), I expect Ethereum network follow the same trend, exactly because some people will switch to Ethereum to solve their problems.
The thing that made me worry was the fact I am quite low on gas because of last month incident and now the fees are a bit higher than my actual gas (of course, I will handle this in the near future).
However, different platforms handle different the problem:
* some make the trade when the money arrives, just the rate may be different because of the market conditions
* some may reject the trade / send the money back
* some have it unhandled
Since I didn't find anything written, I thought I ask, so it'll be in the benefit of everybody.
And the conclusion is, as @libert19 wrote, to make sure an e-mail address is written, so extra headaches are avoided