I think the real advantage of a wasted spark system is when converting to a twin-plugged setup although high RPM needs can be met as well. The problem you would face converting your DME system is getting the appropriate advance and dwell computations from the OEM DME. You would still need a separate controller to manage to coil pack itself. This is easily done very inexpensively concurrently with megasquirt by using a Ford EDIS system salvaged from the junk yard (< $100). However, this would require the addition of a crank-pulley toothed wheel and sensor as well as a MS controller. It doesn't appear that the DME coil output would be useful without some sort of custom electronic logic interface and the Porsche system uses 2 different sensors on the flywheel for its logic calculations. I am not aware of any aftermarket controller that would be compatible with this. The ones that I have reviewed used a single sensor system (missing tooth wheels).
Here is the MS documentation on ignition control and EDIS:
http://www.megamanual.com/ms2/Ignition.htm
http://www.megamanual.com/ms2/EDIS.htm
A look at CNP function including an excellent video on dwell:
http://www.megamanual.com/seq/coils.htm
http://video.google.com/videoplay?docid=-6218245369765754251&hl=en