After deploying your custom Win10 image, reboot the PC and press F11 key. A message appears like "Launching the recovery utility" but the PC boots to normal Win10 anyway.
A special step is needed to link the F11 key to the recovery BCD
Copy the file LenovoBT.efi into the the \EFI\Boot folder on the EFI Service Partition. To access EFI Service Partition, you must first assign it a drive letter within DISKPART. Copy the file into it, and then remove the drive letter.
Why it’s needed: When UEFI platform firmware receives F11 keypress event, it bypasses normal boot order and boots to EFI\Boot\LenovoBT.efi instead
What LenovoBT.efi does: it calls EFI\Microsoft\Boot\bootmgfw.efi /RecoveryBCD to launch the recovery BCD