Plugging in the USB drive did something to the UD7's nvram, now I can see Clover every boot, evrn with no USB present. However, Clover is not reading the config files. I guess it may be the X79-UD7 config dir I created. my blind trial and error. I am annoyed that I compiled a debug-by-default version of Clover, but still no log files. I have NEVER seen a Clover log file.
On the plus side, I seem to be able to boot Windows from Clover.