So little weirded out here. I created a custom ESXi 6.5U1 iso w/ a KS.CFG and modified BOOT.CFG using the below command:
mkisofs -relaxed-filenames -J -R -o ~/Desktop/esxi65u1auto.iso -b ISOLINUX.BIN -c BOOT.CAT -no-emul-boot -boot-load-size 4 -boot-info-table ~/Desktop/ESXiDefaultInstall/
It boots off the CD just fine in VMware Fusion, but when attempted on a VM hosted on 6.5U1 ESXi host, it acts as though the iso is not bootable. Anyone else run into this?