Since the last post I have updated my model and also actually used my upgrade on the street.
I don't remember if I told you in the previous post but the front face of the knuckle wasn't plane so I decided to mount the adapter to the rear face just like the original caliper bracket. I then used spacers to put the caliper in the correct position axially.
So it all worked just fine until I first managed to put a bit of heat into the rotors after a high-speed run. Building up enough heat took more than I thought, but as I did there was a noticeable interference happening between the caliper bracket and the rotor. Looking through the wheel the result of the interference was most obvious for the left-hand rotor and upon inspection I noticed I had radial interference (see highlighted surfaces in picture below).
I'll have to take care of this. Since I seem to have a margin of 5mm between the pads and the outer edge of the rotor I could redesign the bracket to move the caliper 2mm radially but I also want to know what is wrong with my model, especially considering the assembly shows my design should already give more clearance than the classic bubbajoe adapter.