Mounting While Phase Diving Made Easy!

A lot of people may already know this, but if it helps at least one person then it is worth it.

Once you complete the achievement and get your Phase-Lost Slateback, if you have your regular mount bound to a hotkey, you do NOT need to add the Phase-Lost mount to another one. Just use your regular mount hotkey and it will automatically choose your Phase-Lost mount!

(Edit: So apparently you can do this without the mount. I got the mount from the achievement the week before the third cloak skill was able to be unlocked. The wording of the skill seemed to have supported the need for the mount.)