Well, updating grub on sda did not work. It could not find Funtoo. I didn't have the patience to dig into PCBSD's grub configuration, so I proceeded to install grub on Funtoo's drive, which resulted in changing the bios settings on my desktop. :angry: The machine now boots into Funtoo, but there is no entry for PCBSD. Apparently, there is a lot I don't know about UEFI bioses and booting.
I found the setting in the bios that controls which drive is used for booting. The Funtoo installation had changed it. I changed it back to sda and PCBSD booted OK, but still no joy on booting Funtoo from the sda grub menu.
During my searching, I discovered that UEFI bioses usually allow boot drive selection via the F11 or F12 function key. Mine does not. That may be due to the fact that is an industrial system versus a desktop oriented box. To change the boot drive, I have to go into the bios and change a setting.
So, I have two options. I can see about having Funtoo control the grub boot menu for all OSes, or beat my head against the wall trying to figure out why PCBSD's boot menu isn't working properly. I will probably do the former. Fortunately, that PCBSD installation isn't all that critical at the moment.
I will leave this unsolved for now.