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.
but if you will ask them they will say not to use it but the main concern I was having was Gamblers from restricted region who use to bypass it when it's illegal in their country whether their intentions are good or bad the casino will have to comply with the rules.