See in theory the answer would be that Player sticks to the mesh but keeps momentum, as if the mesh is a floor; But getting that in Blueprint is beyond me, I’ve been trying but Matinee seems to be the only approach at the moment; Which isn’t a permanent solution. Everything that has been said in this thread hasn’t worked 
But in the UDK package Sonic GDK they got this flawlessly. As I said I ripped it all open and I couldn’t find how they did it. Its something to do with the “SDKSonicPhysics” but the unrealscript file is empty.