Fascinating... it'd be interesting to see that. I seem to remember reading that Mike Okuda told Shane Johnson that he could modify his TVH graphics to include the word transwarp because at the time there was no reason to think transwarp wasn't successful... but at some point during TNG pre-production it was decided to drop the term. I presume it was because it was deemed confusing and not directly linear from TOS. Also, Roddenberry may have disliked that it came from movies he didn't wholly approve of.
I never really bought the story that Johnson modified the original 1701-A graphics, that entire section of the book seemed like a last minute addition that I'd bet on which not too much time was spent. Plus, the 1701-A's "warp out" at the end of TVH was noticibly different from previous instances and seemed to be implying that the new Enterprise was faster somehow. I think the original idea was that she had trans-warp drive, but as you mentioned, the entire concept was dropped once TNG began production, probably because as you surmised Roddenberry wasn't a fan.