I think step one well before getting to the hard problem of sapience would be showing he had consistent desires and consistent understanding of the world, which would be easy for Data and very hard for even the fanciest current LLMs.
And what might that look like in a hypothetical future where the successors of today's LLMs really do reach that bar and convince you?
Libraries worth of hypothetical future predictions have been made, almost none of which came true. There is no reason to give a hoot about any "hypothetical future" handwaving unless and until it arrives.