Dear NXP,
Regarding the second question - "How do I develop synchronous transmit?", I found the answer myself.
I found this was an oversight on my part, I didn't enable SpiPhyUnitSync under the S32 Config tool.


This resulted in my SPI communication not functioning in synchronous mode.
But regarding the first question - "How can I read or write n bytes (>2 bytes)?", I still need your help.
I don't know who can help me.
Please forgive me for now tagging engineers who have helped me in the past.
Thank you.
@Irina_Costachescu @dragostoma