I've seen many people claim you cannot return to previous Title Updates without Jtagging your console, this however is just not true. It's pretty simple actually and I'm surprised I haven't seen many people do it. You simply download the TU you want from where you want (The Internet Archive preferably, it has all them archived and it's the only place I trust personally.) Use Horizon to put the TU on the USB, take the USB out and put it in your console and move the TU to whatever drive you want to. Then you launch the game and you should be on that selected TU.