i once used maxis wireless unlimited (not home fiber like u) and also have this high latency issue. for my case, instead of routing the connection to japan like u, maxis wireless unlimited connection route to hong kong before back to sg.
using a malaysia based vpn server do help to fix this. but why must we pay extra.

vpn cant fix ur problem if ur connection get routed to japan even when u connecting to server inside malaysia. in my case my connection to server in malaysia did not get routed to hong kong thus vpn helped me. tried and tested the route and ping using pingplot.

if the person u consulted at strongvpn.com consider that all ur connection is routed to japan even when connecting to malaysia server than that person is right in his opinion. every vpn should give trial acc first. my suggestion is get 1 and test it urself first.