Yes I have 3.3U ARGON 1.8 and all backups work perfectly fine. I doubt Nintendo would intentionally brick systems that are modded via firmware update. However they can make it a pain by trying to block them from working. In most cases if they do release a firmware update that blocks backups from working an updated firmware should be released soon after for your Modchip. When new firmware comes out you should always wait till you hear of reports saying if it is safe to update or not.