Two problems

1) you need a lev 55 to grant levels so a raf account would require a transfer onto or for you to get a team to 55 already.

Second i don't see much profit, up untill about level 50 in doing this, taking a few hours for two levels would be sad progress for a raf team, for example just questing I managed to average 1-1.5 hours a level after 45. Prior to 45 it is much quicker much quicker to quest level. Most questers can do 1-25 in 7 or so hours, probably quicker if you were real focused, and of course a booster can do 40 levels in 10-14 hours.

However there might be merit to going the last few levels, say 52-58, since at 58 you level quicker just doing HF than you would making and then granting with new DKs

So yes from a pure min max perspective this might be worthwile for a few of the tail end raf levels.