As I understand it, only Brian had (/has?) the license to install the Kenne Bell with a SHM map in the UK, and then only a vehicle installation on his own premises. No selling on or "sub-licensing" of the map or mapped ECU's. If Dreadnought chooses not to, or is prevented from installing, now or in the future, and SHM is not willing to re-assign an installation license for their map, then it appears that the route of using the KB charger with a proven, reliable ZT260 map is firmly closed.
I assume that SHM have it legally covered, in that if someone buys a Dreadnought converted car, the license restrictions continue to apply, preventing cloning. After all, as second or third owner etc., you did not actually sign any agreement directly with SHM or Dreadnought.
There are plenty of Mustang 4.6 2V supercharging possibilities, also including using the Kenne Bell charger, but as 'colintf' says, the ZT260 map is the problem. For example: https://kennebell.net/products/super...-28-1996-2004/
David