Hi @mary_sergeant, thank you so much for sharing your process in such detail—it’s incredibly helpful, especially for those of us still figuring out the best settings for different materials. I totally agree: having blade recommendations listed alongside force, speed, and passes would save so much trial and error. Your idea of marking the packaging and keeping a notebook is brilliant—I do the same, and it’s been a lifesaver!
It’s great that switching to the deep cut blade made such a difference. I’ve had similar results with thicker glitter materials too. As for your question about blade holders: yes, the iCraft and Crafter machines do use the same blade holders, so you can swap blades between them without issue.
If you ever test the medium blade, I’d love to hear how it compares! Thanks again for contributing your experience—it’s exactly the kind of insight that helps the whole community grow. 
Here is a link from @redhada, for your reference only. Hope it helps! Also, @timmytation , @BellethehowtoGuru, and other Beautiful Ladies may have some notes to share it with you. 