As he wants to fly as a hobby, Sport Pilot or ultralights would be the way to go as he would likely never get past the AME or OKC for a medical. That being said, there is a reason for the fact that seizures are a no-go as you don't want someone having a seizure while flying and crashing into a playground full of children. As a concerned citizen, I would be very concerned knowing someone with a history of seizures was flying around, especially over playgrounds full of children. However, I do not have any children and the last time I was at a playground full of children, the cops were called. But in my defense, there we some hot mammas there so I felt my presence was required. So I am not all that concerned after all... anymore. Sorry for the drift.
Anyways, as I said it is a concern, but if the seizures are under control and if one is only flying by themselves or with only one other person in a sport pilot authorized plane or ultralight, there is little overall risk. Think likelihood and severity matrix RBDM. If you do not know what I am talking about by that, google it. It might make you view certain decisions differently.
I would just recommend that the friend uses some risk mitigation techniques to reduce potential harm. So I would advise no turns around a point over playgrounds full of children. No matter how hot the mammas might be.
I would also recommend that he thinks long and hard about his flying goal and if he thinks it is worth the risk, not only to himself but to others as well. While the risk might be small, it is not nonexistent.
