First, Stardock cannot fixe windows... these limit are related to the operating system, no the game itself...
The game was running fine and there were no slow downs.
for the 3gb , don't need to modify any .exe ... open your boot.ini and add the "/3g" in your boot line... if you have a processor newer that the pentium pro, and 4 gb ram, enable the "/PAE"... it is the 36 bits mode who allow you to move the memory address used by material over the 4g limit...
That should not be required for a game like this.
I feel like there was a memory leak.
I remember simular problems in SupCom.
I don't remember any other game that played up as much.