You're assuming a static price. Why would bip110 coins even be as high as 10 to 1. If theyre dumping at the price they'll mine it'll be even more selling pressure. And if they want a failing coin the...
You need 100 blocks confirmed on the bip110 chain to sell the coins mined in the first block after the split. Assuming no emergency difficulty adjustment is made, which is a hard fork. 100 blocks may take few months to be mined. So at least from freshly mined blocks, there won’t be any sell pressure.