John,
I used o have a nursery in Hawaii, and used the Exacto to graft rambutan, jackfruit, durian, pulasan, avocado, mango,abiu, sapodilla, black sapote, and probably some others I am forgetting ATM...
I found that this tool works best with younger thinner wood. For species that tend to thicken up faster like mangos I would usually not use the Exacto on anything older than 1 year; after that I used a regular budding knife, which to me is much more cumbersome. I always tried to graft everything as young as possible,and the Exacto/Schick combination is perfect for that.