I like Brown where he is for right now too. IMO his primary issue is between the ears. I think he's gotten snakebitten with BABIP enough times that when he faces some adversity he turns into the CJ "ah horsefeathers here we go again" guy. We saw it on Sunday where a cheap double and a walk and things started spinning too fast for him.
I'd probably try and keep him in the role he's in for another ~month, then I'd keep him in long relief but try and push him into higher leverage (come into messy innings, close out a 1 run lead in the 7th, etc.) and then look to move him back towards the rotation.