I'm definitely with topgoon there. That's the approach!
I'd like to see it initiated in prologue and continue throughout the course of play at various intervals. The set up is all there to handle it via surrealist tapole dream or memory flashback episodes, tank matrix or whatever when necessary. I think its simpler to do that in vignette. Not like backstory cinematic, but rather builds the prompts and situational vignettes to service several possible ways in, but where the ways out what's really relevant.
I'm actually really fond of the "defining elements of your character and background by way of the Tadpole getting to know you" angle.
Like NW2's harvest fair, running a largely non-combat tutorial prologue that's based in your character's memories as the tadpole is trying to build a picture of your mind, and letting you tell it what you remember about yourself and who you are - it presents the world space and populates it from that, and it won't necessarily be "right" to what you the player have in mind, because it's not exactly "right" in universe either; it's the tadpole trying to construct a world that you can slip into in your dream state - but it lets you tell the game things about yourself in an immersive way, that can then fall apart into the crashing ship 'combat' section of the tutorial prologue.
Definitely! Have the characterization follow from what happens next in sequence, and the subsequent callbacks references to that. Like the choices the PC makes and then those reveals. I also like the construct where the tadpole is doing its best to present a fitting simulacrum but where the exact details might be fuzzy, cause tadpole lol.
That's what I want though, not just a fill in the blank = silence in the room, but something that develops over the course of play. It's easier to tell a good story with set characters, but the tradition of D&D is not really that. Like I love the Lord of the Rings and the Silmarillion or the Conan sagas, I think they're cool stories and cool characters, but don't really have an interest in roleplaying any of those characters to make different choices than the choices they made in the books. That's why D&D went more generic in the first place hehe.