I wrote a program which turns a square model into a cylinder. This is just a demo. It turned he model generated by Symmetrical triangle generator into a cylinder. I made it a bracelet because my daughter loves it :)
Generating a preview takes a little bit longer (but rendering a model doesn't take too much time). Because of the browser security concern, using the Customizer may bring a message "script timed out". Even you can't preview, you may still use the Customizer to generate a model.
If you really want to preview, download the .scad file and use OpenSCAD directly or find a way to extend your browser's script timeout.
You may customize the zentangle on the bracelet in Generalized zentangle bracelet.