Im not sure about this but should be fine if you ask a friend to send you a RAF invite. The part im not sure about is if you need more then 1 char to get the benefit though.. (Ex. 2 the same lvl + unlinked high lvl when boostin in instances.) I have no XP with RAFing only 1 char.

There is a good write up in the wiki ---> RAF Maybe this will bring some light on things.