I have had a number of successes using bark grafting right through this heat wave. I though I had had a few T-buds that took, but they slowly died after the wrap was removed. However several of the bark grafts are already starting to grow, they include the Ponkan I added to my lemon and the broken calamondin I was trying to save, as well as a Ponkan on my satsuma. I recently got a Meyer lemon branch from a friend that I have also bark grafted to my lemon.

I am trying a variation of the bark graft on one of my marcotted trifoliate plants-- I made a T-bud type slit and inserted a toothpick sized piece of budwood without cutting the top off of the trifoliate. I added a Ponkan and a Meyer to the pencil sized trifoliate. I think it will work.