I can flash the boot partition with the boot.img from the SBF, without issue. However, the recovery.img doesn't seem to work.
C:\Users\user\Desktop\adb>mfastboot flash recovery recovery.img sending 'recovery' (10240 KB)... OKAY [ 0.960s] writing 'recovery'... Preflash validation failed FAILED (remote failure) finished. total time: 2.111s
Failed to hab check for recovery: 0x56
preflash validation failed for recovery