The original CLASP watchband, from which this is derived, did not support the Pebble Steel in two ways. Firstly, the Pebble Steel has a special connector from the watch to watchband. Also, the original script produces a discontinuity between the male end of the clip and the watchband when accommodating very small pin sizes.
This script is not just for the Pebble Steel. If you were having an issue with the discontinuity mentioned above, just select the "Classic" band type in Customizer. It still has limitations, but it allows the user to produce watchbands to accommodate smaller pin sizes.
Click the "Open in Customizer" button to get started.
Thanks to ibudmen for sharing the original product. Open source is great!
The cutout that ensures compatibility with the Pebble Steel also weakened the watchband at the joints. For this reason, I recommend using ABS plastic.
Be careful to avoid splitting the band when removing support material.