Heres my MR-1 with the 3rd baseplate mounted in the pour, cable support mounted to the rear.
I must add in though that these plates have some bow in them across the narrow side. I’d recommend facing the 3rd (rear) plate flat if you intend to tie all three together to utilize the hangers. Otherwise you will need a straight edge and feelers to measure the bow in the plate and then do some Trig to calculate the shims needed to keep the bow with the center point being the highest as I have done. Otherwise you could end up with and 1/8" of base plate removal to get it flat.
