Hi! I attempted the repair with the flex-cable on the top assembly, first only the arrow buttons were not working anymore, I was able to fix this issue BUT ended up breaking the menu button as you described and the adjustment wheels don't work anymore. I would advise against trying to repair it yourself as the repair is very cumbersome, many thin flex cables dangling around while having to remove bigger parts. Plus, I wouldn't say I'm inexperienced as I've already done multiple iPhone, an Apple Watch repair and some other random devices. Do it only if you're certain and you are fine risking to damage the device further during the repair. If you attempt it, plan in a lot of time, took me 3h just to get to the flex cable and if you run out of time or something doesn't work, take it very slow, because that's where I always make mistakes. :D