Yeah I don't think I have seen a double tantrum off kicker.
Anyways, mental blocks-
Overcoming this is one of the most liberating things in riding and the better you can get at doing this the better rider you will become. I can say that its not easy and everyone has different ways of doing it. For me I feel like I make the decision to try something before I even get to the water. Like if I'm thinking about something and start riding without deciding "this is what im going to do" then it probably wont happen. I need time to think about the risk and decide what it is I desire to accomplish. Sometimes I back out of stuff because it's not worth it. Other times the rewards outweigh the risk.
This weekend I was at The Levee and I have had my mind on a bs lipslide on the deck lander. If you aren't familiar with the setup its basically at flat rail that drops off and you go about 10 feet before you land on a wooden deck that goes into the water. The risk: clipping the rail on the way up because its a little bit of an ollie. The worst that would happen is you'd get bucked off the rail then land on your back or head on a wooden deck moving pretty fast. I love bs lipslides though so I felt ready to do the trick. The week before I had bs boardslided it with getting the back lip in mind. Anyways this particular day I had already decided I was going to do it in the car. I warmed up and didn't think much about it and went for it. Got it first try then cleaned it up later. I have something else in mind to add to that bs lip to try next. Might be a few rips before I send it but its incubating in my mind right now
The point is take calculated risk. If you think you are ready go for it. If you can't make yourself do it maybe your mind is trying to tell you something. If your goal is to become the best rider possible you should think about injury. If your goal is to be a stunt man then send it without thinking. A lot of times what the pros do seems crazy but for them its just the latest trick in a slow evolution of their riding and its just a small step. But every now and then you really have to step out of your comfort zone to get that fruit. Doubles I think are a bit like this. No one can make that decision for you. If you think you can do it then I say send it!!!!!