It's unlikely even for most professional hardware devs to develop a home computer in a couple of years*. And he has another job as his main work. The question now is whether it's realistic to expect of him to get this project finished at all. I think that's too much to expect of him, or anyone.
I hope he can team up with a like-minded professional hardware dev instead, so it becomes an accelerated finish rather than a drawn out one.
*That isn't an arm dev board in a plastic box