I am not running 1/28 yet but have seen the MRCG which has a lot of good ideas. I am just waiting for my local club getting to a new place where we also can get a mini z/1:28 track.
My thought is that the PN Racing Mini-Z MR02 Double A-Arm Front Suspension can make the MRCG much more like a 1/12 car?
Have you tried it? and also how many grams are you then adding if you can get it modified to the MRCG?
I dont now how this would affect the camber, bump stear or other thing in the front!