Link can do a dash attack cancel with his bombs and he glides a bit then is lagless right after thrown. You just simply run, dash attack and do what ever you normally do for the Usmash but instead of tilting the analog stick directly up you tilt it diagonally up. Can someone test if sheik can do this too?
I don't see why this would do anything...
In Link's boost throw, essentially, you're start the boost smash animation with a bomb in your hand. The reason why with link, this causes you to slide and throw the bomb up, is because with the bomb in his hand, all A-moves become bomb throws. So naturally, if you boost smash witha bomb in his hand, you're just going to throw the bomb.
...I assume you'd want us to check this out with Sheik's needles,?... but I can tell you right now, it's not going to do anything. I've done the Boost smash plenty of times with my needles charged, but it's done nothing special...which makes complete sense.