@UWPVIOLATOR said in Dell Precision 5530 Compatibility:

It does have Legacy Boot BUT NOT for Internal HD. Thus you must deploy a UEFI image to this model.

One additional comment on this point. It is possible with FOG to PXE boot in bios mode and with FOG deploy a UEFI image with a computer running in BIOS mode (I do this on systems where pxe booting in UEFI mode is broken, but pxe booting in BIOS mode works OK). Just be aware that you can not boot a UEFI image on a computer running in BIOS mode.