(snip)
Can someone please explain how an incorrectly terminated coax with
> some emitter followers speeds the signal transmission?
It helps to give more details.
Note that materials can have an index of refraction less than one for certain frequencies. That doesn't mean that a signal gets through faster, only that it looks that way.
There are resonant systems that, from the leading edge of a wave packet make what looks like the rest of the packet come out earlier than it should. It only works for specific frequencies and wave packet shapes.
-- glen