Most of what Taylor intended (as Abel's art director for VFX) was dropped or abandoned. His concept of vger -- inside or out -- was nothing like what we got, and the space walk was completely different. I think Taylor and Abel wanted Epsilon 9 set on a planet, too (since the live-action for that wasn't even shot till early 79, that concept may have lasted all the way through the primary Abel involvement.)
Except for the interior wormhole, which was completed at Abel but overseen by Trumbull's animation guy Bob Swarthe, most folks think there is nada in terms of on-screen stuff from Abel. But in addition to the refit tweaks -- which did NOT include the self-lit stuff that Trumbull put in along with the awesome paint job -- Abel/Taylor's Andy Probert designed the drydock (though Magicam claimed they only got one general sketch, Probert made available a lot of drydock artwork in STARLOG and ENTERPRISE INCIDENTS) and travel pods and work bees.
The Abel/Taylor bridge probe was supposed to be something much different than we got too. Con Pederson, one of the main supes on 2001 (the unsung quiet one), was working on a kind of light sculpture. About 10 years ago, I talked with a guy who, like Probert, managed to survive working at both Abel's and Trumbull's, and he mentioned he liked hanging out with Pederson because the guy was all about the work, whereas a lot of Abel folks at the main facility were more about the drugs (I kind of make a hobby of trying to interview as many TMP folk as I can, and since I write about tech stuff in filmmaking, it actually happens pretty often. Haven't gotten too much in the way of revelations, but you never can tell when somebody is going to peel back a new layer.)
There is a guy named Joe who worked on the show and wrote a letter to STARLOG saying the NEW WEST article about Abel (look that up, it is something else!) was in large part malarkey, and it supported a lot of Abel views that the problems were all over, not just on their end. Brick Price has also gone on record about Abel producing a lot of footage, whereas the official story is that they produced nothing but an unsuccessful film test, which was when Wise started getting rid of them.
We really need that Preston Neal Jones 1600 page making of TMP, now more than ever!