Speed is hard to improve,you have it or you dont!
Oh really? Well, the Legend of Zelda has lots of swag, especially since there's a creepypasta on Ocarina of Time and Majora's Mask concerning the missing player, B.O.B.
does shadow boxing improve hand speed?
Shadowboxing with free hand weights with tighten your technique, thus increasing better timing and speed......YES
of course it does, fools think it doesn't doesn't know what he is aiming for and how to properly do so for speed, technique/speed/foot work/cordination/hand-fist improvements/etc...if you know what you are doing shadow boxing is a great work out, someone out of shape can't do 1 round of shadow boxing
It can, and that's with the natural, gradual, muscle memory, so it will happen even without hand weights.
But of course your technique has to be proper.