Stuck? It does really work on that way which you would need to transfer those tokens first into that exchange account before you would able to make trades.Just like whats being done when you do trade on Delta.It isnt stuck as long you do have the gas to spend on or ETH balance into your own MEW and with the exchanger. Same as being said above going in and out isnt really a problem there might be difference in gas but somehow you can able to adjust it according to your needs.