Just give it a try. This part of FAI (or setup-storage) was programmed long time ago from someone else, so I do not now it this may work or if it was planed to work.
> swap or /tmp. I wondered if it's possibly trying to do the cryptsetup > stage before LVM is fully ready? We can live without it being in LVM, > I just wasn't sure if it was a simple configuration mistake on my part. -- regards Thomas