I’m wondering why some casino discouraged the full use of VPN while others fully support the use of it.
Casinos do not want issues with their players, and they don't want to have issues when it comes to compliance; they want to be within the regulatory boundaries, so they want to know the location of every player that played on their casinos, and those casinos that support the use of VPN just want to attract players to their casino because gamblers, if they have a choice, want to use VPN, but there's a possibility they are going to make a shift; I have seen it happen, and we have seen complaints about changing their terms on the use of VPN.
It is about keeping reputations of such casinos equivalent to say that they restricts the use of VPN so that they don't act as accomplice to some regions where the government has termed gambling an illegal activity.
So being so cautious, they wouldn't give you that access on their platform if you are using a VPN because it assumes you are anonymously trying to maneuver your regional or the casinos TOS by changing of your location.
So take note that such casinos are more transparent than those you seems giving access to VPN because some of them knows the implications they players may face when get caught. So literally what they just needed was your money being deposited of played in their sites.