I'm concidering purchasng the Samsung S8+, and am concerned about the Phantom 4's controller clamp.
As the Samsung S8 has a curved screen edge....

Will the Controller phone Clamp hold the phone correctly without damaging, or, impeeding the screen?

I have an S8+ and it fits okay BUT my s8+ is in a case made by Evutec.  I haven't tried it without the case.  The only possible issue I have seen is that if you aren't careful, the mount will press the Bixby button if you close it too tightly.