Make repack firmware of multi csc firm without tripping knox

Hi,

I just want to know if it is possible :
I'm working now on an official multi csc firmware (PDA N910FXXU1BOC5 and CSC N910FOXX1BOC2).
In phone info, my csc is "MET"

As you knox, oxx's firmware are multi csc firmware, and set "MET" as default when the csc of the phone in previous firmware is not included.

I know CSC's partition is on "cache.img.ext4" of the firmware. So, I just want to know :
Is it possible to extract cache.img.ext4 of the firm, delete every csc you don't want to switch to, (eg. for me I want XEF csc's, so I will let only this one). Repack and flash it, whitout tripping knox flag ?

Thank you in advence