Jay Thanks this helped a lot. For some reason having the installer create the EFI partition and later replacing the root partition with a cgd partition didn't result in a bootable system anyways (i'm not sure what i did differently the last time).
One of the main problems with the old full disk encryption howto is that seemingly the installer can no longer be used to perform the installation at all as creating the disklabel on the cgd partition and telling the installer to use it will just jump back to the main menu without doing anything. Currently i'm not 100% sure what's the best way to deal with it. Of course the procedure laid out in the post you linked could be used but it's a little cumbersome. Currently i'm saving the contents of a minimal installation to the USB dongle i'm installing from and copy this to the encrypted root later but it doesn't seem overly elegant either.