I've heard from *sources*, who I trust entirely, seeing as we worked with them on this project, The main reason for delay is exactly that, The control/ride systems.
They had planned right up until recently to use the existing system with a nice new control board. however due to issues with the launch tunnel show scenes, this couldnt be done.
Correct me if im wrong but the existing launch tunnel show scene was triggered by an actual sensor on/near the track that detected the train was about to enter the tunnel, for the new scene, this could not be done as the onboard audio starts as soon as the train is dispatched and this needs to line up with the audio in the tunnel/effects.
A new system has been installed and all effects are currently being programmed/timed, best visible example of this is the water jets, they are the same jets, same system, different computer controlling them and therefore timings need to be re tested/inputted, the new trains and speed would mean this would of HAD to have been done on the old system anyway.
I also understand that because of recent issues with the launch scene, the trains speed/launch speed is being changed as of this week. An example of this is the re-testing with dummies in the past few days.