If you are in such a spot that you had to cancel 20% time already, and this person doesn't get it that it is time to buckle down and get to work, best to let hi

If you are in such a spot that you had to cancel 20% time already, and this person doesn't get it that it is time to buckle down and get to work, best to let him go before he can do any real damage to your goals. There's more to being a lead developer than just having coding skills and technical knowledge. If he is immature enough that getting bored gets in the way of his work ethic, he has no business being a lead developer at all. On top of that, if in your entire 50 person company there is not even 1 task that interests him, might not be such a good fit in general.