Hi,
I would recommend contacting SEGGER support.
I don't know what tools you use, but for example, J-Link Commander can program a data file to a specific address in the flash.
https://wiki.segger.com/J-Link_Commander

I just tried that with an .srec file generated by S32DS2.2 IDE and I could place some constant values to an erased flash sector.
Regards,
Daniel