Soon you can happily exchange Grin for BTC using Bisq 
Yes, we are working on some plans to make life easier for exchanges and users alike. Note that at the moment Grin can be perfectly exchange if a user withdraw to his/her own wallet and then to TradeOgre. We are however looking at some methods to make it possible for users to directly deposit to exchanges from their mining pool without transferring to their own wallet. A method that does not depend on a custom implementation like the one from Gate.io, but one that would work universally.