It seems to me that a good place to start would be to choose a well-known component and open a GitLab/Codeberg/GitHub account for the various "layers" involved, one repo each:

• Hardware design
• Driver
• User Interface

(I'm guessing here as to what those layers might be obviously)

You'd need one person to act as "captain of all the things" at first, approving pull requests etc., but eventually some star contributors will emerge and they can be deputised to run particular repos.

After a while, you've got all the components you need to build that one piece of equipment from scratch, at which point, you adopt a new piece of hardware and repeat the process.

My background is web software, so obviously there will need to be modifications to the above, but as most anything that can be designed must first exist as a text document of some kind, git is an ideal tool for this sort of thing.