After Episode 4, I'm going to do some case training on easy; that way, when I start my EX game, I can just blaze through the rest of the Episodes and get Episode 5's feats with no problem. Too bad I have to also do Episode 6. Heh. Anyway, I should be able to get some chips that way.
In Episode 4, after Aya sets the last of the C4, the team that defeated the Twisted in there get trapped in.
Maeda: M-my calculations were wrong. The building's g-going to blow. There's no escape!
Uh, okay, and this pertains to Aya how? She could just, oh, say, Ascend?
Jesus Christ. I mean, I know the badass (Deus Ex Machina) helicopter scene is after that, with the f***ing awesome music, but, like, the whole thing doesn't pertain to Aya. It's a big WTF moment.
My only guess right now is that Maeda and Aya didn't want the soldiers to die, and were going to find a way out for them until the last moment. Still, the face-value version of the scene is steeped in stupid.
Take this with a grain of salt...and some possible spoilers (I know it is the topic title, but better safe than sorry)...
1) It could be one of the limitations of overdive--line of sight is needed for it to be successful. Even in real-time, overdive needs a direction and focal point. CTI had the technical means to accomplish it. Aya probably needed to see a target for overdive to function in real-time. When she ascended in the past, CTI was able to guide her back. For real-time overdive, a physical body within Aya's proximity needs to be present.
To further illustrate the "line of sight" suggestion, we can observe how Aya ODs in the field. I think she has an extended, yet limited, sensory perception of her environment; she is able to "see" (or "feel") available OD targets within a specific radius. If she were to OD beyond that radius, her consciousness could be lost in time indefinitely. She cannot OD into a target she cannot visualize or feel.
2) It could be through the influence of Hyde. He stated that he was in Aya every time she did an overdive, possibly to ensure her safety in the past and to be certain that the survival of his species would be guaranteed. Him residing in her was a tether between the past and the present (i.e., Hyde). As long he existed in the present, Hyde could guide Aya's consciousness to him, wherever (and whenever) she was.
Feel free to correct me as well, but I think Hyde mentioned that the High Ones were connected. With each death in the past/present, his power increased, which was basically a signal for him in the present to "coax" Aya to his location.
How he is able to exist in two places (in the present and in the past inside Aya) is something I will ponder for another time.
Also, if I remember this correctly, Hyde was responsible for the construction of the overdive machine. It was based on, and had components from, the central overdive system of the Babel. Only he knew how overdive functioned. It would have been simple for him to manipulate this phenomenon to suit his means.
To keep it within the boundaries of the game, as mentioned in earlier posts, you lose everything when you ascend--a restart, so to speak. Aya had the luxury (comfort or security in the knowledge) that if she became overwhelmed, CTI would pull her back to the present. She could attempt the same mission(s) repeatedly until she was successful. Since CTI no longer existed from Episode 4, failure was no longer an option. A real-time ascent had to have a conclusive, favorable outcome.
I believe Toriyama is the head writer, and the other names you listed are responsible for making his vision a reality. More than likely, he has the final word on the direction of the story.
Even though Nomura is credited for character designs, he probably has the most influence with this story (and possibly all stories from SE). Possibly, Toriyama agreed to any "suggestions" Nomura might have had regarding T3B.
I think it is more along the lines of when does he use that power and how often he uses it. He may have more input than we believe. On T3B's title screen, he is credited as the character designer. But, he is also the creative producer.
He started out as a game debugger and now has quite a few credits to his name (e.g., anything related to FF VII; FF VIII; FF X and X-2; FF XIII trilogy; KH series; Chrono Trigger). Based on his successes, I feel that he does have some degree of influence with any SE game.