The deposit made in BK8 will be credited 100% in special bonus with a requirement of 6x? I understand that a minimum wagering requirement is the deposit +100% and this is x6, isn't it? Regarding BTC it is very encouraging that they do not have any withdrawal fee, this means that in case I want to make a deposit without wanting to take the bonus and if I win 50USD in Bitcoin, I have the right to withdraw the total money without any rate? BK8 is raising a lot of level, there are many looking to play here, if they put as their main slogan that their bitcoin withdrawals are free, this will call many people to play.
It's right!
And even though the commissions for bitcoin transfers are currently small and the cryptocurrency market in general is quite calm (even despite the hype created around the Merge ethereum update

), the complete absence of commissions is a strong argument to attract new players who own bitcoins. And those people who do not really want to bother with the use of altcoins.
But many owners of bitcoins do not like to open accounts on crypto exchanges, exchange bitcoins for altcoins, also losing money on commissions by the way. Then, vice versa, change altcoins to bitcoins. In general, these are all unnecessary troubles that are not needed.
So of course BK8 needs to advertise as much as possible the absence of commissions for withdrawing bitcoins.
It is also useful for maintaining the reputation of the largest Asian casino and for creating a positive image among the players.