The big problem I have found with scandoublers is they get VERY hot. Why is this? It is because they do it in a rudimentary way to keep the cost down? If money was not a consideration, surely it wouldn't be hard to get a 15Hz signal, input it into a SVGA graphics processor and produce a 30+Hz signal?
As I understand it, your bog-standard scandoubler literally doubles the 15Hz signal, surely inputting the signal into another processor for output would keep the things from running so hot?