As far as I’m trying VPN on region blocks (like jToS), you won’t get into trouble as long you’re not making a big mess (includes RMT, destroying server’s economy, and such)… I know few Indonesian friends in Klaipeda/Telsiai and they are still there, just not playing ToS for a while. Those who get banned are mostly ones that get famous by doing VPN and getting some troubles like selling Silver… Getting famous on Youtube and said you’re using VPN is obvious action to get banned aswell…
This is not new problem, We have 1000 MMOs and Mobile games, within same games there are multiple servers. There will be superior (by this term: more players, more money, etc) servers than others…
Even RO suffers this problem, which you can’t believe that RO servers are still exist, but it’s in dead city situation with just $1000 players invested inside said server… It’s the root problem and business model that needs to be fixed by most game developers + publishers…