They accept VPN and even allow users to change usernames but prevention is better than cure and if you can use their service without VPN, why do you need VPN and use it if you are aware that VPN can cause some kind of troubles in future?
That means users can safely use a VPN and there won't be any problems. But that will be up to each user because some users still want to use a VPN while others will not use a VPN to access their sites. It is about someone's comfort in visiting casino sites with or without a VPN.
As long as using a VPN is not a problem for Duelbits, I don't think it's a problem either, but you really have to ask their service support if you can use a VPN and provide reasonable reasons why you use a VPN. Indeed, some people always want to appear anonymous, so they don't want to reveal their original IP. whereas in my opinion it looks like a child, but as long as it makes him comfortable there is no problem with me.
It's also important to confirm that Duelbits doesn't ban VPN use if that's not a problem I think using a paid VPN is the solution because it guarantees more security than using a free VPN because I've used it and it sucks having to share with other people and it's hard to access the site in the end That.