[aappleby]

They can't do the work because they copied the firmware from some other company's product and don't actually know how it works.

That other company probably also copied it from somewhere else, etc.

[leetbulb]

Yeah. They, too, likely hired someone to reverse engineer it to make their own modifications. Let's add another to the chain. Surely the firmware could only become more "safe" with Lego block hacks. That's the point, right, OP?

All things considered, it sounds like the "gyro board" module is probably something that is OTS and already certified for use in a healthcare product. Wonder what the legality is of modifying such a thing in such a way?

As others have suggested, make your own or use a more ubiquitous module from the open source community. Integration wise, Claude can probably get you 80% of the way there.