My opinion comes from experience and getting things certified but also common sense and observing enforcement patterns (the latter of which is most important until they overstep and get challenged).

Go back to my example: Does a one-off product need to be certified to be transferred to the people that paid for it? Keep in mind, best case, this will add a roughly >$10k fixed cost to the sticker price.

It's a general principle in common law that the law makes sense. The popular, sophomoric, and extremely conservative interpretation of the FCC rules makes no sense by way of being extremely costly for no discernible benefit, either to the seller, the buyer, or the economy at large.

There are things that are battery powered that need to be certified and things that are not kits that don't need to be, though, so I'm not sure I can agree with that wording.

But 47 CFR § 2.803 gives an exemption for "evaluation kits". I don't think that clearly covers boards used primarily as single-board computers (and not genuinely for evaluation), and I'd guess that's why the Pi developers got certs for their boards. I believe it's the best argument that this board wouldn't need certification (or verification), though.