Hello again friends. It's a Supermicro server with S2600GZ board and current BIOS/IPMI firmware. Followed the Wiki on installing from USB. Have downloaded 6.0.1 three different times and installed elsewhere with all three so the ISO is good. I have tried with a USB stick created with etcher, mounted virtual cdrom iso by KVM and virtual iso in IPMI. Have futzed with BIOS settings and USB legacy, UEFI modes, Legacy, Both, etc. We can install just any OS (Centos, Windows, ESXi, Ubuntu, Mint) here EXCEPT proxmox 
Could there be something I need to pass through to the kernel -- is that even an option from the PROXMOX installer grub menu?
Could there be something I need to pass through to the kernel -- is that even an option from the PROXMOX installer grub menu?