In my book Messerschmitt Me-109 Volume II from 1942-1945I have found this in it:
The Bf-109G-1/R2, G-2/R2, G-3/U2, G-6/U2, G-5/R2 (G-5/U2), G-8/U-2 used the GM-1 power boost system
The Bf-109G-4/U3, G-6/U3, G-8/U3, G-10/R2, G-10/U4 used the MW-50 system.
However no where in the book does it say that they used both systems. The Bf-109 did not.