To regain access to the MSET exploit, someone would need to patch the FIRM too. Unless you know what you're doing, you won't be able to do it. We can't use the FIRM from 4.x (the firmwares where the exploit is available) on newer firmware versions because the FIRM has changed significantly since then. If I recall correctly, the newer save and ROM encryption methods are in the FIRM, so using a 4.x FIRM on a newer firmware version would break too many things, if not brick the system. I don't remember where I read it, but I think one of the hacking teams (I think it was KARL3DS or RxTools?) is going to try to patch the newer FIRM so it supports the MSET exploit.Impossible, the mset exploit was patched in 6.X FW version. The only way to gain acces again to such exploit is reinstalling an old DS profile .cia from the 3DNUS I believe.