At the end of the day if you strip down all the awesome features that make the GlowForge unique it’s a 40-45w CO2 laser. What this means for you is that if you want to find out if a material or technique will be possible, and that does not depend on any of the novel functionality of the Glowforge and fits within the basic working envelope, you can search on google to see what others are doing with 40-45w CO2 lasers.
Here is one article on laser cutting rubber stamps:
And here are some materials:
This should totally be possible, and I can’t think of any reason it would not work as it’s already being done on lasers that are less powerful and far less awesome than the Glowforge.