Hi,
after some initial reading, thinking and experiments regarding
UEFI support in Tails, I've come up with a first set of goals and
non-goals I believe to be reasonable to start with.
Quoting 
https://tails.boum.org/blueprint/UEFI/:
Goals
-----
* devices produced by Tails Installer should boot on most UEFI-only
  hardware (e.g. some relevant set of Macs)
* devices produced by Tails Installer should boot on most hardware
  that only supports UEFI boot for GPT devices (e.g. ThinkPad X220)
Non-goals
---------
* UEFI DVD boot: BIOS boot from DVD works fine on most hardware,
  including Macs; adding the files needed to have UEFI DVD boot work
  on some systems will break what currently works for others.
* UEFI boot from hybrid ISO cat'd on a USB device: given BIOS DVD boot
  works generally fine, it's OK to require users to go this way and
  install their UEFI-capable Tails USB stick from DVD.
* Secure Boot support is not part of this plan. Picking technical
  solutions that leave room for Secure Boot would be a great
  bonus, though.
Does this make sense to you? Anything you'd like to see changed?
Cheers,
-- 
  intrigeri
  | GnuPG key @ https://gaffer.ptitcanardnoir.org/intrigeri/intrigeri.asc
  | OTR fingerprint @ https://gaffer.ptitcanardnoir.org/intrigeri/otr.asc