I tried getting the usual navigation path, then use circle tangents and navrays to modify it into a path that counts for turning radius. Sort of worked though I stopped for different reasons (I was making my own movement component as I was trying to use box collision for a semi-physics pawn but doing proper replication takes too long so I gave up).
This way it doesn’t matter if the character movement can snap to direction, as long you do the navigation right and not allow it to move without one you are set.
Since this was first google showed me it is not necroposting, leave me alone! 
EDIT: I read about A* navigation that takes gradual turning into account but not sure where…