Great tool for videomaking, thank you very much for creating this! :) My only gripe is the roll axis being linked to yawing with non-level pitch (so basically, if you're looking up or down, the camera will always tilt/roll while turning left or right, which cannot be easily countered during smooth panning shots)
If you're still looking for feature suggestions, I'd love a way to bind either FOV (zoom) or DOF Distance to different inputs.
If you just want generic ones like "5m up" that Kunos makes those are more doable, you could just disable the yaw/pitch/roll controls and log the changes in position. I'm not actually sure what the timestep between lines in the spline is though.