My Name Is Legion wrote:
No, there's nothing special about the nacelles on Excelsior except in fanon.
Nonsense. The Excelsior was designed as an experimental transwarp vessel. So by inference, the nacelles -- unlike anything we'd seen before -- must have been for transwarp purposes.
What *is* fanon is the association of the failure of transwarp technology with Scotty's sabotage. There's no reason the technology shouldn't have succeeded, based on what was seen in STIII.