Any casino can be used for money laundering. It is enough to deposit dirty money, and play a few games (depending on whether there are wagering restrictions). When you withdraw the same money, it is already considered a gambling win. In a way, that money is no longer illegal.
I just wanted to bring this up, as a possible reason for additional KYC checks.

If you are a regular gambler, I think you shouldn't have a problem with Duelbits, considering their reputation so far. However, keep in mind that half a million is a serious amount and any mistake here is expensive.

OP, if I may ask, I assume that you used other casinos before, did you also play with large amounts and maybe get banned or excluded from any of them for any reason?