Dougboy's post, #53 in this thread is as 100% correct and accurate as any post on the subject can get. There is no chance of the series being successful. It MAY get off the ground, (I hope it does not). but it cannot be sustained in the present environment.
The TT itself succeeds because as has been said, it IS...THE TT. Other races latching onto the side of it will be poor and weaker cousins of the TT, and (even more serious), may contribute to permanently harming the TT if (God help us) anything goes seriously wrong.
Whilst I admire entrepreneurial initiative, and the DED are to be at least congratulated for making the effort, I feel in my bones that this is a no hoper.