@Tom-Elliott
It seems I made the disastrous decision to assume that the variable I saw online in another post was a FOG default-created and set variable, so I’ve been using it assuming it had been assigned the correct IP. I made that assumption because the first menu item I created, the original Ubuntu ISO, had worked, so I was just reusing what I had “working”.
I changed the code to just the IP, because of that DNS issue and your question, and now I can successfully boot the extracted ISOs. Now I have a slew of other things to deal with therein, but at least now I’m there.
Mint and Ubuntu (extracted) need some work to get running, but Hiren’s runs perfectly,