If they found you are coming from a restricted region then they will suspend your account immediately no matter how much funds you have in it but for high gamblers its not gonna work because you have to submit KYC also so VPN won't help.But if you are just bumping your IP then it's not a much problem.
Depends on the casino where you are but with Duelbits, I've read before that it's totally fine as long as you don't have any other actual violations that you've done. And for someone who's seriously gambling and you've got the intention to use VPN, it's best to ask first if it's allowed or not.
So, whenever you win big or hit on a something, you're not going to have any problems and you'll have the idea of what you're doing is allowed and fine.
Where do you read this? Duelbits allowed the use of VPN but not playing from restricted country. There’s many usecase of VPN and one of them is for privacy for purposes that’s why many user use it even if they don’t live on restricted country to access the casino. This is the case which Duelbits allowed the use of VPN.
But for those whose using VPN to bypass country restrictions will surely be penalized when caught by Duelbits team since this rules is clearly stated on the ToS. Allowing such players will put Duelbits license in jeopardy because they have legal obligations to restrict thise players.