Yes, bootloader unlocked, with all the checking Wu describes in his Install Notes.Hi, cannot recall trying that only but will give it a go...I assume with booltloader unlocked...?
As I understand, with bootloader locked you might be able to flash a full, stock firmware. Anything else requires unlocking bootloader first, and putting up with the nag screen.
I would think being able to flash something that doesn't work right (won't boot; boots funny) would prove that the bootloader is unlocked, but it's possible you can always flash, and they really mean "bootloader unlocked" and it's only the loader that was ever locked, the "flasher" was always unlocked. But that's not the way people talk about it behaving.