The closest thing seems to be the mouse (for clicking) and it's cable.
And cables in the floor under the feet (if any).
There should not be a difference in comfortably clicking when placing the sticks horizontally and away,
and likely better feeling (EMF wise). Shielding usually makes things worse for me, so you could try without shielding that mouse. Also the shielding can transfer EMF closer to you.
I also see you tried making wheels ?
The pink ones ? Or what is that for ?
So we originally built the mouse rods out of wood. The problem was that the wood flexes and my wife really wanted extremely accurate and sensitive feedback in order to be able to draw with the mouse. So we found the aluminum pieces that are extremely lightweight and don't seem to cause problems because of the wood in between them. We tested the wood and the aluminum back-to-back and there was no noticeable difference for her.
The pink discs are weights. They counterbalance the weight of the rod so that the mouse on each end is almost weightless. That reduces the friction and makes it feel almost identical to using a regular mouse.
The mouse that she uses to control the contraption is a regular mouse that I stripped all the guts out and glued elbows to to be able to connect it to the rod, in case that's not clear.
Another thing that might not be obvious is that on the bolts that connect the aluminum rods to the wood between each layer there are washers with bearings built into them to reduce friction even further. They weren't cheap, but again it's all about reducing the friction to make it feel as natural as a regular mouse. These aren't the ones we got, but it gives you the idea. https://www.amazon.com/Bearing-5x11x4-5-Miniature-Bearings-VXB/dp/B002BBQ604
As the next step we are going to build the horizontal clicking mouse to get the mouse and cable farther from her and see if that makes it better.