What about the possibility of adding an inversion and making the trains floorless? Technically it can be done and the space (however small) is there.
The potential of Oblivion being made floorless or having its track layout changed has been discussed numerous times in the past and neither of these things are likely to ever happen.
Making the shuttles floorless would require extensive modifications to the station and queue-line areas whereas altering the track layout to incorporate an inversion would require wholesale changes to X-Sector as a whole.
The main reason that I believe neither of these things will ever happen is money. Merlin wouldn’t cough up the money that would be needed to make these changes unless they thought they would see a significant return on investment. There are numerous dive machines around the world that are both floorless and have inversions so Merlin wouldn’t be bringing a USP to the table if they did alter Oblivion, in my opinion it would be money wasted that could be spent on things that the park actually needs.
Oblivion was the original dive machine and in terms of ride hardware and structure she needs to be left as she is.