So... You don't write with language models... You have a language model write for you... You can spend all the time you like developing structure and ideas, but if you don't actually do the writing you haven't written it.

This is spectacularly wrong headed. If you want a book with your name on it for adulation or career reasons, but lack the interest, time or talent to produce one - hire a ghost writer. Writers are affordable and plentiful.

Similarly if you have a hyperspecific interest, kink or genre preference - use your position as a presumably well remunerated tech person to hire a writer to cater to it. Trust me, we need the patronage.

If you're looking for the pleasure of writing, you will unfortunately have to undergo, as all writers have through history, the process of suffering and discovery that we call writing.