Unfortunately there's no way to do that, I too am looking for masterware, and since much time, with this software you can manage many other stuff and not only the display. Moreover I don't have your problem using 90 degree viewfinder on my 6008AF , but I use the T type that is a bit different from the 90 degree standard.
It's unbelievable that this item is unobtainable, a stupid cable and a cd .... Sometimes on e-bay is possible found the "Master Controll unit" that probably can do the same of masterware, but I don't know if it works well also on my 6008AF or not, It seems was projected only for 6008 Integral.