Unfortunately, as babygun said above, we shouldn't expect this feature to be added. Although it's a really interesting idea since such a feature could be helpful for players. By the way, some exchanges such as Binance and Kucoin have a feature that allows you to convert small balances of assets into a native token. So if Betfury had the desire, they could do something similar by allowing users to convert small balances into BFG or BTC. In addition to that, they could also charge and burn the BFG tokens as a conversion fee.
This is possible since Web 3.0 casino is flexible in terms of DeFi feature. They already had built im staking and farming so a DEX will be easy for them if they want it. But since Betfury is almost account less website and the blockchains available on it chage only few transaction fees. I don't see the point of adding an exchanger if you can just withdraw the funds to your wallet then exchange it on DEX since Betfury only charge the actual transaction cost for each blockchain which is very low compared to Ethereum and Bitcoin. Besides you can select network of the coin you want to withdraw that gives you flexibility to withdraw on a cheaper fees blockchain.
Best example here is Bitcoin. You can withdraw in Native blockchain or in Bep20 BTC