Hi @StephenW ,
Currently, the ISOs have to be in root of the template/iso. The easiest way to accommodate this is to symlink the files. For example, if you have:
/mnt/iso/windows
/mnt/iso/linux
Create: /mnt/iso/template. Or /mnt/iso/pve/template/iso - this way you can point PVE to /mnt/iso/pve...