Since a few have responded I figured I should through out my setup as well too.
For as long as I can remember, we have always ran Flexi and PM on separate machines. Reason being? Primarily location. We run a dedicated design station in my office and have another computer running PM in our print room. Also nice not having a big file you are ripping effecting you working on the next project. Since we started doing this it was never a problem, and in the last actually printed manual I have (Flexi 7.5) it even states it as a feature.
So we are upgrading to Flexi 12 (perpetual, never the other option) as well as setting up a new rip computer. I upgraded my design station and installed PM on the new computer and it wouldn't load. Ended up being that I still had the old rip computer still running and PM open. Contacted tech support and ended up getting a call and was told that doing what we do was never a feature, it was a bug and it was fixed in version 12. Well, its now working as I want, and according to my 7.5 manual it was a feature, at least at some point in time.
It apparently looks like my usage case is in the minority at the moment, but for larger shops I don't see someone sitting at the same computer to design that is also running multiple printers and plotters.