To my mind these have basically identical meanings: expressing that something is not physically possible. This is actually stronger that simplying saying it hasn’t happened. Consider:
I will not go to Liverpool this year (very likely true)
I will absolutely not go to Liverpool this year (very likely true)
I cannot go to Liverpool this year (false)
So if anything I would expect this analysis to point in the opposite direction.
What distinction are you drawing between
cannot spread it to you
and
can never spread it to you?
To my mind these have basically identical meanings: expressing that something is not physically possible. This is actually stronger that simplying saying it hasn’t happened. Consider:
I will not go to Liverpool this year (very likely true)
I will absolutely not go to Liverpool this year (very likely true)
I cannot go to Liverpool this year (false)
So if anything I would expect this analysis to point in the opposite direction.
The distinction I’m drawing is that “cannot spread it to you” is ambiguous between whether it’s shorthand for:
Cannot (in any circumstances) spread it to you
Cannot (as a rule of thumb) spread it to you
Whereas I think that “can never spread it to you” or “absolutely cannot spread it to you” are harder to interpret as being shortenings of 2.