Despite the similarity in airframe design, the underlying FC system are quite different... It is for the same reason, that it is unlikely Tuna will ever develop a Plus version of UAV Toolbox.
I've tried everything to upgrade my firmware in my typhoon H+. I tried the Global OTC. I made sure that the internet wasn't filtered. I made sure that the memory chip is working in the unit. It just doesn't recognize that there is an upgrade available.