The only problem with noddon would be if the competitor donned the blindfold simultaneously with doing moves, which would be very hard to judge. Maybe the competitor should be required to touch the blindfold with their hands before solving, or wait for a judge to say yes (which would be bad because it would slow times but it would make it more fair)
Alex I think if they did that your times would be at the mercy of your judge's reaction speed! But it's still tricky to tell if you moved before the blindfold. I think right now they could give a +2 if you OBVIOUSLY moved before the blindfold went down. Otherwise, I think the judges should be lenient
Taking an idea from hypixel. When you do use nod on, you use it at risk. If you're suspected of cheating by a delegate then if you use the nod on, there'll be no negotiating. Though you can still use it