I emailed thompson last night and they got back to me this am. You're correct, the triangle piece is to bolt to the caliper and acts as a rest for the caliper. Hopefully i'll start working on this thing soon.
'08 10R, Lime/Black
Flashed ECU, PC5,WBC, custom shift light, shifter w/co2, cat delete, V&H slip-on, BMC race, lowered, stretched,-2/+5
MORE TO COME