If you set the MSC to rf ID 10 for sure and i think it works on 11 as well (I use 10 on my configurations) then you can assign all 12 ports and blaster 1. This definitely works, I use it this way in my own system with 3 PVRs that all use the same ir codes on ports 7, 10 and 11 with an MX980, MX6000 and KP4000 and have no problems controlling the unit that I am trying to control and no others. I haven't experienced any of the other issues you mention so I can't comment on them.