so far we have not used the Rowley Crossworks IDE for any projects.
Most of our Build Environments are prepared for four different compiler/linker/IDEs like gcc/make, Eclipse, Keil and IAR. In case of LPCXpresso54628, let me recommend to use either the makefile or the MCUXpresso project and put the different settings like include paths, compiler flags, linker flags manually into your IDE.
Btw: There is no need to adapt the PostProcess for your IDE. The PostProcess is used for convenience in order to adapt the project in case the color format has changed or the screen orientation has changed. In your case, when you have selected RGB565 and one ScreenOrientation, then the include paths and the libraries will not change.
I hope this helps...