Casinos are not as strict and compliant as exchanges, so many of these flagged accounts by authorities often elude their radar. But some of them might want to use that as an excuse not to pay their customers, thereby monitoring those flagging activities for their percuniary gain. For this, it's better to avoid a direct mixing wallet for any direct business or activities.

Wait a minute, if not for foolishness, why would someone complete the KYC and still mixing their money? The best is to send the money directly, but credit his crypto address with either bank transfer, card or P2P, so that the address will not be linked to his other crypto assets.