If we are to even consider the replies on this thread on recommendations for the platforms that accept the use of VPN, I don't think there are suggestions made and if any at all, they are not many, gambling platforms don't usually demand or take in the use of VPN for their website, but Incase we see some that allows for that, maybe they are just new in the business or doesn't have enough resources to employ for the measures that take care on that.
Most of the new casino is the one that very strict on VPN users
because they are strictly complying with their license and at the same time to protect their casino from multiple account abuse.
You certainly do not know what you are talking about regarding where I boldened in your statement above. Are you telling me that the licence is a reason here, that the authority would mandate the casino to restrict an account to the local IPs or not allow VPN to access them? I do not think so. VPN itself is good, it enhances privacy and even authorities know the porosity and threats to privacies online. So it is not a crime to use it in almost all countries of the world.
To date, only a less countries like Iran, Turkmenistan, North Korea, and Belarus, which are not even popular with casinos thought it to be illegal. Many casinos allow the use of it but for the issues of mistaking it for many accounts by the same person when the IPs generated by it clash. That is the only downside to the use of VPN in my opinion. We should also ensure to avoid it if our casinos specifically forbid it.