PXE/iPXE install for Proxmox VE?

That certainly does look promising, but why is Proxmox putting itself in the way of PXE installs in the first place when the code it's based on (Debian 13) has great support for PXE installation? The tutorial there seems more like a workaround to a problem Proxmox is creating and I don't understand why they're doing that.
 
I doubt the validity of that assumption. fetch and iso are no standard linux kernel parameters but just forwarded and processed by initramfs scripts.

IMHO I dont believe that PXE booting a PVE installer is common enough usecase for getting implemented right now.
But I spotted this part in the init script (line 284ff), so someone at Proxmox was thinking about it already:

Bash:
else

    cdrom=

    initrdisoimage="/proxmox.iso"

    if [ -f $initrdisoimage ]; then
        # this is useful for PXE boot
        echo "found proxmox ISO image inside initrd image"
        if mount -t iso9660 -o loop,ro $initrdisoimage /mnt >/dev/null 2>&1; then
            cdrom=$initrdisoimage
        fi