Going through proxies will only work so long as the protocols for the psn used on the serverside do not get updated or that the psn authentication keys do not change, otherwise it wont be able to connect no matter what proxy you throw in.
This is even true with debug consoles, once they are downgraded below a specific version (2.30 if I recall correctly) the console will no longer connect to the psn because of either protocol changes or keys changes.