If there is an "objective" meaning to our lives which is without recourse to an inside-out view, then we have no access to it.

Occam's Razor, fewest entities/assumptions, etc is so problematic, because it is not invariant to being re-parameterised. I.e. under one description X is more complex than Y, and under another Y is more complex than X.

Here is Roger Penrose talking about the fine tuning of the Universe:

https://www.youtube.com/watch?v=yDqny7UzyR4

Many use these observations to argue for design. Say it became a scientific consensus that design was the strongest hypothesis, because it just kept making good predictions. Design implies purpose. Would life still be meaningless?

Is this all just a regress to "nothing is just as good as something therefore all life is meaningless"? I think that's where you have to end up to defend Nihilism.

A more complex hypothesis isn't useful until you come up with a method of testing that will distinguish it from the simpler hypothesis. That doesn't mean you have disproved the more complex hypothesis; just that you shouldn't use that hypothesis until you actually have a need for it.