Men have told me that edging is a tricky, timing experience.
He gets to the edge of a climax and his body takes control of the situation that's a natural body function. The other mechanism problem is getting close to orgasmn many times and holding off has caused dull sensation caused by too much sensation in a prolonged state of denial.
I wouldn't try it with someone that has a hard time reaching orgasm.
Too each their own that has enjoyed edge play and know what they are getting into.