I liked the idea of a cable clip on the top rail, but didn't need the runout sensor mount. I took Arturis's top rail part and removed the runout sensor mount portion. I also reduced the gap to make it clip on a little stronger without the need for the bolts and I increased the thickness of the tab that goes on top so it doesn't break as easily. I was successful with PLA, but it will be less fragile with PETG or other materials. With PLA you still need to be careful putting it on and removing it or the tab can break.

Print lying on the flat side. No need for support. There will be some slight bridging for the notches, so having good bridging calibration can't hurt. Printed with 0.2mm layer height.