I don't think so - the bootloader signature verification will still reject the zip file, as the partition is (technically) locked.^^Yup.
Looks like the dd command is used to facilitate the transfer.
You think this will also flash from fastboot?
I'm really not sure how HTC is allowing us to circumvent that verification now, but I'm glad they are
If only we could crack that bootloader, we'd be able to undo the red text on bootup, and fix the digital watermark. But that'll require an hboot exploit that may never come