Online courses for a spooky reactive horse

Hi all, anyone have experience with Glenn Stewart's online course or the TRT method, from Tristan Tucker?

I have a 5yo OTTB who would be much safer and more fun if he would relax. He gets very excited around other horses, bucks, crowhops, is highly reactive.

Will he ever grow out if this? Or could he learn through these courses to be calmer?

Any experience would be welcome. I would like to field hunt him, but I think he'd literally explode if I did.