Looking for: best way to procedurally create an endless waterslide

Hi everyone, happy new year!

Completely new to Unity and everything gamedev, so thanks in advance for your patience. I am looking for a way to procedurally create an endless waterslide. I have found loads of tutorials on how to make endless runners along planes with an automatically moving player object, but that's not really what I'm looking for.

The game I have in mind uses gravity to slide a player down a slide with occasional holes in the ground, which need to be dodged by left/right inputs.

When following the aforementioned tutorials, I tried replacing the plane elements with an arch created via ProBuilder, slightly rotated. However, this makes the placement of the spawn trigger for upcoming arch tiles too complicated for me.

Any ideas or pointers where I could find help creating something like this would be much appreciated! In any case thanks for reading and have a great rest of the weekend!

Cheers,
Dominik