I've done something similar with my MB-D100, and it certainly makes a big difference to how well it mates with the camera body.
However there is still a problem with tripod mounting - the MB-D100 itself flexes quite badly. Take the batteries out and look into the chamber while pressing up on the tripod mount with your thumbs - it flexes visibly, and I think this is the main source of the problem.
It is a pity Nikon didn't design it on some sort of metal subframe, but instead they just relied on the innate rigidity of the plastic shell, with some ribbing, or fillets, to to stiffen it up a bit. Unfortunately it just isn't enough.