If you didn't think the QR15/tapered blade fork I was working on was weird enough, check out how weird it looks with a post-mount brake setup (customer is generously letting me experiment a bit on him, but even after I get it figured out a bit better it's still going to look pretty weird...)
After spending some time messing around, it became clear that due to the high precision required, putting the threaded bit into the posts first wasn't an option (no matter how precisely you miter and join the posts, there's going to be enough distortion to pull the end of the mount out of line, especially the lower one). If you install the posts first, then do the threaded inserts (in this case stainless M6 nuts from the HWS, I think M6 pulley mounts would look nicer though I worry about having enough surface area for the brake to mount to) you can make sure the brake will line up right.
The cool thing about the QR15 dropouts is that they line the blade up much better with a post-mount setup than most standard 9mm dropouts.
Oh, I should also mention this is for 160mm. I would hesitate to do 180 or 200 on this setup (though you could run an adapter) just because the posts get even longer. 140 is obviously no problem.