After upgrading Output Manager from 2.0 to 3.0.4 PCL printers started to print very slowly from PostScript data.
The INPUT_COLOR_IMAGES parameter has changed the default from NO to YES, this change was done in Output Manager version 2.5.
This resulted the color data to be processed in color instead of rasterising the images.
Since the PCL printer was a Black and White printer it does not have the needed processing power to handle color images the printer paused where the color pages were in the print stream.
Adding parameter INPUT_COLOR_IMAGES = NO into the Job profile results the behavior of Output Manager 2.0, allowing the printer to perform according to its specified speed.
UPDATED: November 22, 2017