You could test for the difference between angles of the line and the rocket being positive or negative, then have a sub event that interpolates in a positive or negative fashion.
I did try smoothing it with LERP(Dash.Angle,Rocket.Bullet.AngleOfMotion,5)
but lerp will only turn clockwise, so you'd need to filter into two sub events and test if the difference is positive or negative I think.
That would smooth out the turning. :)