Yes, I would have expected the 45 deg taper to take out any movement you would otherwise have in the headset, however, this has not been the case for my IP-036. My IP-056 is fine however.
I thought about this earlier, and it is possible that I have a mismatch in the taper angles, there are both 45deg and 36deg bearings out there. Wondering if XMIplay got either the wrong integrated cup or bearing and my real problem is a mismatch of the taper angles.