hello kobe_nein,
since there’s cboot functionality to load device tree via filesystem.
you may copy the device tree binary to the target, modify /boot/extlinux/extlinux.conf, add FDT entry to specify the new device tree binary path, then reboot the system to make change.
please see-also CBoot chapter, and please check [Kernel Boot Sequence Using extlinux.conf] session for reference,
thanks