Why don’t checksums or fills work when generating a binary output?
Some MPLAB® XC compiler features, such as those to add checksums or to fill unused memory locations, are fulfilled by the Hexmate application, which only works with HEX files.
If you are generating a file output that is binary, then the file will not contain any codes inserted by Hexmate.
If you do require a binary output and these additional compiler features, then it is best to generate a HEX file and use a third-party application to convert the HEX file to a binary format.