My teacher Rolf Eichinger used a technique which I think was new in rosette-making although it was surely used for making wide purfling or decorative strips in other fields.  The fact that the “logs” are not glued to each other but are glued to a veneer strip allows them to bend into a circle.  There is a limit to how tall a design can be and still bend without breaking.  Here is one more picture just for aesthetic value, nothing like a nice sharp plane.