I just ordered a Phantom2 V2 with Zenmuse 4H-3D and will arrive in 2 weeks. The ad says the H4-3D is for Hero4 Black (another ad said H3-3D is for Hero3). I have the Hero 4 Silver and decided to go with H4-3D. After the fact, I see that Hero 4 Silver is 146 grams and Black is 150 grams. I am assuming that the Zenmuse balance will be off just a little (4 grams). What is the better way to balance it out? 1) drill into the counter-weight and remove about 3 - 4 grams? 2) or add 3-4 grams onto the camera case? Does it really need to be "perfectly balanced" and add/remove EXACTLY 4 grams or is it good enough to just add 2 grams or so? Everything is new to me, so I just want to cover all the bases before first flight. Thanks!