...and one more thing (scale debate related):
Where was Excelsior
assembled? Given the apparent shortness of time between ST II and III obviously not in the orbital San Francisco dockyard because this one had been occupied by the Enterprise
at the beginning of ST II (and seems to small to accomodate Excelsior
If it had been constructed at Utopia Planitia would it not have at least required an impulse drive "trial run" to travel to Earth?
Can we exclude the possibility it was assembled inside Earth Spacedock? Our protagonists seem rather surprised to see her there at the beginning of ST III, as if they had been totally kept in the dark that Excelsior
was soon to be ready (plot hole?). Or was that the "public restricted" section, accessible only to Excelsior
personnel (e.g. Janice Rand) which exclusively witnessed the return of the battle-damaged Enterprise
from the Mutara sector (another delicate topic).
Of course this may explain a few things. They assembled the ship inside Earth Spacedock but totally forgot that it wouldn't fit through the spacedoors.