Time is a bit tight at the moment. I hope you don't mind to wait a bit for a review.
To make the review easier, can you fix some image links?

ERROR '/assets/images/tutorials/debo-3d/final.webp' not found.
ERROR '/assets/images/tutorials/debo-3d/Rescaled.png' not found.
ERROR '/assets/images/tutorials/debo-3d/SatinColumnLockStitches.png' not found.
ERROR '/assets/images/tutorials/debo-3d/final.jpg' not found.
ERROR '/assets/images/tutorials/debo-3d/SatinStitchBoundary.png' not found.

No rush. Updated image links. Will probably update the tutorial to create a triangular end region on the satin columns and then stitching over them, rather than narrowing the satin stitches to a point. Other suggestions for improvements are welcome.

ill probably update the tutorial to create a triangular end region on the satin columns and then stitching over them, rather than narrowing the satin stitches to a point. Other suggestions for improvements are welcome.

I'm really happy you say this. Actually this was one of my concerns for this tutorial. I just don't have the brain power at the moment to really think about it. Claudine may help too (but she too is a bit busy right now).

Yes, I was travelling, and could not really test your tutorial, sorry about that.
I also think it would be great to have a foam version of this font with so-called planks and caps. You may read https://www.mrxstitch.com/3d-foam-machine-embroidery/ for more information, and you could use satin with some randomness for that.

@claudinepeyrat06 Thanks for the suggestion and the tutorial link.

Thanks for taking this on! I have never tried foam or hats at all myself, although I have a machine with a hat attachment and some foam. Just haven't ever gotten around to learning it :)

It seems like you're using a quite light-density foam in your tutorial. Is that a foam designed for embroidery?

Also, I thought it was common to let the satin stitches themselves cut the foam and then tear it away, rather than trimming the foam after tacking it down?

An introduction would really help, telling the reader that this tutorial is about doing 3d puff foam. It might even help to give an overview of the whole process to let them know what to expect before they start getting into the steps.

Got some embroidery foam, regular foam is a bit easier to find but more time consuming to use. Will update the tutorial for embroidery foam.

@lexelby Attached is a simpler example based on https://www.gnu.org/graphics/winkler-gnu.html which is available under the Free Art License

Preview image:

To make it, first stitch out the License text using a thin needle and thin thread - if thin needle and thin thread are not available, the License text could be done using a regular size font on the side of the cap, rather than the front of the cap. Then stitch the GNU part, this is a regular satin stitch (GNU layer). Place the embroidery foam on the hat, and use a satin stitch to perforate the foam (horns-cut layer). Carefully remove the foam, moving the hat as little as possible. Finish the embroidery to fully cover up the foam (horns-cover layer). It is also possible to skip the horns-cut layer and just use the horns-cover layer, though the results are less clean, small bits of foam may stick out.

With 3mm thick foam, minimum viable puff stitch width is about 4mm, so GNU is not done as a puff stitch. The above uses 40wt thread and regular needle size. You may need to slow machine down a little. Maybe this would be a good first puff foam tutorial?

@claudinepeyrat06 The present tutorial could follow up as a second foam tutorial, as adding planks and caps maybe too much for the first tutorial?

A first tutorial is at #3957