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...
Unfortunately, I compared these particular TNG graphics with the Johnson ones. They are the same (judging by all the technobabble numbers), only that some guy put an Enterprise-D
schematic over the Johnson Enterprise-A
schematic. I just hate this kind of fraud!
But anyway, if the okudagrams on the bridge of NCC-1701-A at the end of ST IV did not say "transwarp" than there is no reason to assume it did have transwarp.