All I know is it splits rounds with abandon.Fluting probably has its advantages...less contact surface area to 'stick' while the basic principle of the wedge does the work. I suppose the flutes could do some filling and 'grabbing' with the channel filling with straight grain material, but I thinks it's a good idea to have on the sides of a wedge. No doubt, it's a homemade wedge. If you get tired of it, send it to Ga. If nothing else, I'll backfill the flutes with a MIG welder or stick welder in the shop.
Stump rounds are always the worst. Put that wedge in and it's over.