RE: Center shot and paper tuning
The roller guard places more lateral torque in the riser. I thought I had excess clearance for the vanes I use so I milled the inside back edge of the roller guard bracket to allow the rollers to pull towards the center more. I have about 3/16" less fletch clearance now. I shot the bow after re-assembly and it grouped 2 inches to the right at 20 yards. I kicked the rest out so it was a little more centered and the groups again went into the center.
I think there's been too much emphisis on Blazer clearance lately and has influenced the design to accomodate them.