@george1421 Thanks a ton for those words (OK that iso image seems to be only a legacy/bios boot media.)
I figured out one thing I was doing very wrong.
I was PXE booted in UEFI… when hitting F12 to boot the PC, I automatically selected the IPV4 under UEFI, and not the “network boot” under legacy, both of which show up in my F12 menu. Both of which FOG PXE boot works with.
Well, after using the legacy, the dell iso image (that only shows CD.txt) works flawlessly. Now I think everything will work that requires legacy for me, as some things seems you can’t use PXE UEFI with (perhaps not supported by the manufacturer, some programs like Memtest require spending thousands of dollars to get the “site edition” that works with PXE, etc). Keeping in mind your words in other posts about the size limitations of isos (2gb?), the ones I wish to use should all be small enough. I think we can mark this as solved.
Thanks so much for your help.