Is there a feature in the making to convert between the two cryptos on the site, without needing to buy something with one currency and then sell it in the other? I understand why you can't have a dollar in both currencies on two merged markets. That would cause huge headaches with people getting ETH when they wanted BTC or vice versa. I have some BTC on the site, but I would prefer ETH.
The withdraw time is just to slow to shapeshift the currencies ourselves. If converting on site is not possible, could a feature be added where you supply an ETH address to a BTC withdrawal or vice versa. When the admin releases the funds he could shapeshift it for you. This prevents paying for two transactions when one would suffice.