At the request of our users, we are now working on adding a feature that will allow users to choose the base currency of WinMiner, that way, you will be able, if you so wish, to keep your balance in BTC and withdraw in BTC without exchange fees.
Hope this clarifies
with 2 accounts one base currency BTC and a spare account in USD we can get the benefit when BTC is low and when btc is high we can mine on spare acount USD