Peter I did request an cruise altitude change because PFE will not assign me even thousand altitudes for westbound flights.
I and others have experienced not getting descent instructions after having made a "step climb" request during the cruise. In my flights now I do not use the "request higher altitude" function in PFE. If I need to step climb I just do it without requesting it. PFE won't nag you like the default ATC.
I believe Proflight2000, when compiling a plan will assign 290/330/370/410 as Eastbound routes, and 310/350/390 as Westbound routes, changing the cruise altitude you set in PF2000. It (understandably) takes no account of areas of the world where the divide is North/South rather than East/West. Nor does it account for RVSM. But after you have compiled, and before you connect to the sim you can change the cruise alt in PFE.
Peter