Given the kit is already full of tenons, there wouldn't be much room for storage of mahogany tenons, if any. As for the extra tenons and cutters, whether those are useful would probably depend on how much you use the Domino. Cutters will wear out over time if used enough, especially the smaller ones, depending on what you use the Domino for. I have not had mine nor used it enough to wear out a cutter or use up enough space in the kit to make room for a different type of tenon. I hope to though, so I bought the tenon/cutter kit with my 500. It gives me flexibility on what size I use.