You might keep your eye on https://answers.unrealengine.com/questions/98750/beam-emitter-use-local-space-not-being-checked.html they’ve labeled the issue UE-3358 but so far no fix in 4.7 
You might keep your eye on https://answers.unrealengine.com/questions/98750/beam-emitter-use-local-space-not-being-checked.html they’ve labeled the issue UE-3358 but so far no fix in 4.7