If I'd allowed an unschooling structure with her-- NO WAY could she go to college. And she needs to go to college, because her inclinations and interests (and dare I say-- her vocation) lie toward the hard sciences. That's not 'self-study' territory in a larger sense of wanting her to become independent and self-supporting as an adult.
Anyway. I think that if your gut is telling you that he needs an hour or two of externally imposed structure each day-- DO IT.
Agree with HK. I think of this like driving-- keep one eye on what's immediately in front of you, but one eye on what's further up the road toward the horizon. 5 years from now, your DS will need the skills to follow instructions and work within some structure in order to have access to the full range of opportunities he might want. Start building now the skills he'll need... and he'll get there.
DeeDee