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.