I think what Jimi got exposed to in England was the use of effects and techniques with them, which he took to new heights. Beck can get more sound out of a fender amp by itself than anyone.

I don't know about Miles. His shadow looms over 3 decades of Jazz so large that it's almost impossible to determine where it all came from. He was the leading edge of 3 or 4 movements in Jazz. Blow by Blow and Bitches Brew are pretty much considered the definitive fusion albums. Blow by Blow didn't leave my turntable for months.