Right, this is why I think people assume "first principals" means "first [learned] principals." It is almost always super high level and used synonymously with "back to basics."

And fully agreed on your reasoning on why these are good phrases to keep in mind. I think I would pile on to the "becomes an iterative process" to highlight that "starting from first principals" is more likely to be where folks start. With advanced solutions expanded to cover more and more details that the initial assumptions could gloss over.

I think this is largely justified, if only because "first principals" meaning "absolute foundation" are almost certainly still being discovered.