Personally, I could see this being how the supports and track are built - in the following order:
Phase 1: As we know, phase 1 was the building of the Batwing/Cobra Roll Element & the inversion under the station as well as the station track.
Phase 2: As we also know, phase 2 was the track above the toilets which included the pre drops from both lifts and half of both inversions which make up the inverted drops.
Phase 3: I would of thought they would want to get the track in underneath the maintenance shed before long as they have to have the maintenance building up a ready alongside the station (of which is having continuous work carried out on it). This
could include some sort of secret element/track. This could also be completed before the main season starts (
if X-Sector is to be open with the start of the main season) so that if there is a secret element it won't be revealed to the public as the park isn't open.
Phase 4: Could be done at the same time as Phase 3 - This phase is getting most of the middle section of the coaster done. This includes multiple inversions and elements; the first drop, both Dive Loops, both bunny hills, the Corkscrew after the Batwing, the mid-course break run, the sea serpent roll, both corkscrews (could be classed as a barrel roll of sorts) after the Cobra Roll & the final break run and track leading into the station.
Phase 5: Final construction phase which would see the vertical lift & first lift hill being put up into place along with the remaining track for the second inverted drop.
The reason it could be done like this is
IF X-Sector is open at the start of the season there is enough room for the crane to put up track in the centre section and then final phase can be done with the crane coming from the access road to the left of the construction site. Another reason why the lift hills may be last is that we haven't seen any lift hill track on park as of yet whereas there is a lot of other track for the inversions and whatnot.