Yeah, I don't think you get better bang for your buck than with 6112. And nothing stops you from pairing that with MRR rear. That was pretty much my Plan B.
I also think that the MRR, on paper, is the best mid-range setup handsdown because of the adjustability. It should also be all that you can realistically use on the 4R unless you move to the areas around here
Back before 2020, its price was quite reasonable but I have no idea about the situation today.
