VPN is a very bad idea for gambling because sites detect duplicate ip for various user. The best is to use a dedicated server which its own ip address.
Someone already pointed this out and its not more on the duplicate IP but, more on the risk of compromising your passwords and user log ins since when you enter those information using VPNs, it passes through the VPN first before it goes to the target site. Not really a good idea to use those when transacting anything related to Cryptos and other Currencies.