There's an exemption from Section 1201 for "Computer programs that control devices designed primarily for use by consumers for diagnosis, maintenance, or repair of the device or system".
Are you allowed to share how you repaired the software? Because if not then what I said stands, he cannot sell these little Raspberry Pis or publish information on how people can build them themselves. That's one of the problems Louis Rossmann has been talking about in regards to the FULU bounty program.
I see in the "final rule" for 2024 (PDF) a section titled "11. Computer Programs—Repairs of
Devices Designed Primarily for Use by Consumers", although it seems to indicate that nothing changed, as opposed to telling you what stayed the same.
I actually was just reading up on it yesterday because I've rooted a commercial e-ink word processor and was trying to sort out how much about the process I can legally share. The sibling post has the link to the LoC rulemakings that define the exemption categories. These exemptions are the same basis for any phone jailbreak, which makes me suspect it could be legal to publish methods as well as do it your self, but I'm still unsure.