Smooth turns in survey waypoint missions

Hi, I am at the very start of my journey into finding the best/most economical way to build a multi-rotor that will need the same smooth waypoint flying as you do. I want to build to fly a small blackmagic camera and have come across references in Urdu pilot where it describes the spline curve it can plot through waypoints, this might be useful for you to follow up on. https://ardupilot.org/copter/docs/mission-command-list.html.