This is a spectacular design. And if you use white PVC, just grab some red tape and make the bases look like candy canes. I could also see HDPE adapters folding into this design, to have pixels in the bases too.
I have run many experiments with what lights to put inside the RBLs. And 8 rectangle pixels is the bomb for pixel folks. Super bright, 24 LEDs inside with 8 pixel channels, and they burn the same power as 8 bullet pixels due to the heavy losses in the load resistors of the bullets. I'll be hanging mine under the eaves behind the icicles this year. But I love this pathway idea, so it's on my list for 2018 !!!
For those who want to make up the 8 rectangle version, I cut a 3 3/4" piece of 1" gray electrical pipe. Then I cut a 3.5" piece of the 3/4" gray electrical pipe. I used these two pipe specifically because they can be inserted inside each other with no costly adapter. You have to sand the leading edge of the 3/4" piece so it starts to fit into the 1" easily. Make a mark at 1" down on the insert. That is how far you want it to go inside the 1" pipe. This leaves 2.5 inches sticking out. I bought a can of the gray PVC glue that is made for these pipes. Put a small amount inside the 1" and then with a hammer, drive the 3/4" piece in. If you carefully heat up these parts, they glue together more easily. But be careful. With the warmed up pieces, I had one that slipped in so good I went past my 2.5" mark. One of the pictures shows the two gray pipes glued together. This one had a shorter top section (1" pipe) for a bullets test, but that one held too many bullets and the power would have been high per RBL. My finished wands for the rectangles will have the 1" top gray pipe cut to 3.75" long.
This picture is your result when you zig zag the 8 rectangles around the 1" pipe. They have a sticky back but also use a tie wrap around them to make sure they don't slip. I will also be using a tie wrap around the lower pipe so it does not slip out of the RBL's light clip. The pictures also show 5 and 6 rectangle versions starting from the left. The 5 was not at all what I wanted, so I ended up also making one with 10 bullets. In testing, the 10 bullets were the weakest, followed by the 6 rectangles and the winner is clearly the 8 rectangles. These pictures are dumb nodes for the experiment, but when the pixels arrive I'll make up 30 of them.