There was also as I recall, once an attempt at a moving belt for load / unload, that caused more problems that it solved and was quickly turned off and covered over.
I recall something about the ride track having a set of fog machines thru the ride, to create the effect that the cars were "riding on clouds" but that also was nixed just after being turned on (don't know if it was removed or just turned off, but always wondered and wish I could find a photo of said effect.)
I never heard any plans that called for a reason to shorten the ride track (for the current version) due to ADA compliance on the 2nd floor. I did hear some some things on the original version of the ride was planned to take you "UP" to the 2nd floor (Alia, world of motion) but that never got farther than concept art work.
I've heard plenty of reasons as to why the 2nd floor was no longer used after the referb due to ADA compliance
(yet, oddly now we have a pass-holder lounge up there, so... what does that tell you about the ADA thing.. hmmm)
Still pains me to this day.. I'm old enough now, to have a kid.. and he will never get to see the wonders I saw at his age, for the first time at Epcot on that ride.