i don't think od is essential for your pf. if my opponents pf wants to shoot from outside, i want to let him do it, because if he misses, he is weak on the offensive rebound and the ball is mine. my pfs are 2-3 on od, and still haven't been killed by opponents pfs outside game. the only thing i am afraid of is the mismatch on pick and roll, where he is left against pg or sg...which can be neutralised by a zone anyway.
p.s. i really hope i'm right, because training my pfs in od would be a torture for me