THat’s interesting because I read a post from CalDigit on Twitter the other day saying that they didn’t know of any docks that did.The USB-C Pro dock does. My CCC backup drive is connected to mine. I know you can boot from it because that's how you enable encryption on the CCC backup, by booting from the backup.
I can't imagine a reason to buy one of these, really. Unless the power output capability trumps everything else, why would you ever choose 2x HDMI over 2x DisplayPort? The ports are exactly the same, otherwise.
I’ve gone back to look and it seems they have corrected themselves: