just for the kernel flash you can use the -R option.
if it's not working the doc says:

"When flashing the eMMC content, the safe way is flash the eMMC/VANILLA image first, then remove battery for a moment, and then flash the FIASCO/Rootfs image. Do not boot up the device between the two i.e do NOT use the -R parameter at the end! "

so first try the kernel flash with the -R option.
works --> okay
not works -->flash the eMMC image first and afterwards flash the kernel again WITHOUT -R param