So you would do that? You would make him go in - drag him, shove him, pull him, strike him?
You seem to be ramping this up to the most extreme edge of possibility.
There is a such as thing as sympathetic jollying along.
Or empathetic, loving but firm, "I know you don't want to, and I understand it, but you still have to do it and I'll be here for you every step of the way".
If you do not have the right tools to bring this specific child to a place of doing what he doesn't want to do, life in general and HE specifically could end up being a tough parental row to hoe.
If you join HE groups to give him and yourself connections, he may well be exposed to families where learning, or anything at all, is done solely if the child wishes it so. Sometimes that has to be factored in as a potential influence that can complicate matters for a parent. It's not just the kid that can be influenced either. Where coercion is redefined as having even secret, non vocalised ideas about what you'd like you child to learning/doing/achieving..... it can impact people who are already quite conflict/"getting kid to do what they don't want to do" averse.
When you are teaching him yourself, and he is aware that all that stands between him doing what he likes and having to struggle with long division is to down tools and watch you flounder, your best flounder impression may well be on the cards.
You want him back is school, so I presume you want him to keep his skills aquisition up to date ? In HE you are the only person that can make that happen, and you are potentially bedding it down on a foundation of him believing that if he doesn't feel ready for the ball proffered, he can refuse to kick and you may not have the tools to get him to just get on with things. Or even go back to school eventually,
One of the things perhaps less often discussed in HE is the degree to which it shifts conflict into the parental/child relationship. Becuase suddenly there is nobody else doing the heavey lifting motivation-wise between your kid and the stuff you want him/her to learn, or know how to do.
Where there is a notable reticence to manage a conflict between parental and small person wants, and a tendency to assume the parental tactics will have to become heavey handed to be successful... IME that is when the path of least resistance tends to be the new route on the table.
Which can mean a parent's original vision of how long HE would be for, and what form it would be in, is jettisoned.
I am not saying that is 100% your future in HE. But I think it might be worth thinking about the extent to which perhaps you are under tooled in a "getting kid to do what he strongly doesn't want to do" context. You'll likely need a greater range of tools between the feather and the hammer. An awful lot of people start HE with quite a rosy idea of sitting around the kitchen table being joyful(ish) about fractions. Quite a lot of those people get a rude intrusion into the daydream when a kid hones their evasion tatics and appears to be secretly working on a PHD in Winding Parent Up With Mega Procrastination and Tearful Flopping of the Oh This Is Just So Unfair Kind.