Multi-arch installer

[Ian Eure]

I have some oddball hardware I want to use FAI on.  It has a 
64-bit CPU, but its UEFI BIOS only supports 32-bits.  I can 
manually install with the Debian multi-arch image[1], which has a 
32-bit bootloader, but correctly installs amd64 kernel and 
packages.

Is there a way to get FAI to do something similar?
[1]: 
https://cdimage.debian.org/debian-cd/current/multi-arch/iso-cd/