I would like to create this kind of effect where the geometry is thicker in one end of the spline and thereafter goes smaller together with geometry. Probably matching the sphere head. To add to this the splines are moving so preferably this should move with growing splines. I'm using geometry on the splines from Redshift. In C4D there is a spline option to control it.

Could someone point me in the right direction?

Here is a test that having the basic idea. Right now the heads are growing with the poly wire. I wish to have more control over it such as stopping heads from growing, shaping them with ramp etc. Is there a simpler way to create it?