Kernel Debug kit (KDK) file can't be copied in Big Sur 11.1 Beta 2 (20C5061b)

In Big Sur 11.1 Beta 2 (20C5061b) we can't copy kernel development file to required location - /System/Library/Kernels/ the location is READ-ONLY here.

Even with SIP OFF we get error.
sudo cp /Library/Developer/KDKs/KDK11.120C5061b.kdk/System/Library/Kernels/kernel.development /System/Library/Kernels/

cp: /System/Library/Kernels/kernel.development: Read-only file system

Tried copying in recovery mode too. Same error persists. "Read-only file system"