> Perhaps ext4 was the wrong choice as the default for the LiveCD then?
Why do you think so? GRUB doesn't understand LVM either and LVM has
default for a long time in Fedora.
LVM doesn't give the issues we are seeing today - most people giving Fedora a go with the LiveCD won't have a separate boot partition. If we need to keep the DVD and LiveCD defaults the same then perhaps the switch to ext4 shouldn't have been made until GRUB can read it.