Have you ever tried live with him? I know you'd prefer not to but sometimes a prey animal moving around is really what is needed to get some snakes interested. My fussy eater was my male borneo, after five ish years I think (knock on wood) he's finally accepted f/t rats as food and eagerly strikes and feeds. But no amount of dancing or heating or different prey options really helped over the years and if I put a live rodent in it was taken instantly every time. Are you pre scenting the room with feeder beforehand for awhile so he's good and revved up?