Sweep cut on helical path with circular sections

Hello members,
I'm working on a project that requires me to make a vibratory feeding bowl. The bowl has helix and circular sections connected by spline curve (I've tried bridge curve as well). I have performed sweep cut on helix-circular path.
The problem with it is that on the junction between helix and circular paths, the curvature is very unstable. I have put G3 spline. There are fluctuating peaks on the curve analysis. Hence, the feedback from workshop is that I try to smoothen the curve so that they can machine it better. Can anyone suggest me ways to have better sweep cut. Also, how can I analyse the model to verify it before sending to for machining?
Thanks in advance.