Is it possible to repeat a shape layer (let say a filled square) and have it follow a non-linear motion path (or other shape layer)?
It looks like a shape layer's Repeater can only duplicate in a line?
To get the curved motion path:
1) Create a separate null object;
2) On the null object, draw a mask in the shape of your motion path;
3) Copy the mask from the "Mask Path" of the null object;
4) Paste that onto the position parameter of the shape layer, and it will generate keyframes for you, which you can then adjust to your preferred length of time.
And one way to repeat the objects is by pre-composing the shape layer:
1) Pre-compose your shape (with the motion applied to the shape layer);
2) Duplicate the pre-comp as many times as you need;
3) Offset the pre-comps in your timeline by however many frames you'd like, and voila!
The shape repeater uses offsets based on X and Y parameters for position, anchor point, and scale. Since it's just simple math and based on single values for each frame you can't give a different position for each duplicate.
You can, however do a neat trick that might get you where you want to go.
There you go, a 12 step process for repeating a shape layer along a path.
I've used a loopOut() expression to rotate on a path without extra steps.
I know from your work that you have Plexus. Look into lights, custom sprites and spline type beams. Don't bother with any of the longwinded workarounds.