Inlet and outlet nozzles on the stationary frame is the most common arrangement (indicates 2 pass) and the easiest to pipe to/from. While 2 pass configurations are possible with one or more nozzles on the movable frame, I doubt anyone in their right mind would want to do it that way.
However, multiple pass units have to have one or more of the nozzles on the movable frame, depending on which pass is multi-pass, if not both.
Nozzles on the movable frame require special attention to the piping to/from those nozzles, since due to the compressibility of the gaskets, the nozzles can be at slightly different locations each time the unit is closed again. Not impossible, but you have to design it very carefully.
BTW, P&F's typically don't like to have to support piping loads. Unsupported piping loads can cause the frame to twist and cause the unit to leak. Do your piping support right the first time.
rmw