Quote - Well 6 hours of trying and I apparently don't understand how motion blur works. That was only 4 trys though. I'm just going to have to work this out, outside of the scene.

Is your object actually moving?  I just did a quick test in 8.5Pro with a ball.  Set the position at 0 sec on one side, at 1 sec I moved it to the other side.  Turned on blur with 6 additional frames and it worked like I expected.