I am boosting 4 sets and they are getting all the Raf xp. I do sfk at level 10 till 20 then 20 to 40 in Sm.
Useing a level 70 druid not linked to the accounts. Haven't had a problem.
At level 20 they do only get like 200+ xp per kill and it goes up as they level to what I think is a maxed at 384 per kill. Might be 484.