We don't do that here, but instead imbed writing within the Engineering
courses. That way if they fail the writing, they fail the course.  I
like that better than the pseudo-link I worked with in Architecture
where the writing component was a separate 30% that was evaluated
separately.  The catch for students there was that if they failed the
30%, they had to repeat the whole course.  This made the writing
component the "gate", and the writing instructor, me, "gatekeeper".
Charon is not a role I relish, and not a role I relish for writing.  It
makes it into a hoop. (In practice, students very rarely passed one
without the other, but those few instances, and the more general
perception, were quite problematic).

Having two separate courses does address some of the problem, but I
think you still wind up in the awkward division of style and substance.
A student might appropriately respond, "If I've got the substance well
enough for Prof. X, what is _your_ problem?" After all, learning is
about substance.  I think we only achieve a real marriage of style and
substance when we say, unless substance is clearly explained, it is not
clearly understood.

Your proposal sounds interesting.  Keep us posted on how it goes.

Rob Irish