I came across a video of someone using a 3D pen to decorate a few things. That got me thinking, and I did a search on making trees using those and found some really neat videos. Have anyone here any experience in using a 3D pen?
I have seen some videos of similar products, and yours is an interesting point. I would be cautious about using it for the leaves and foliage, but it may look cool for an old and twisted tree trunk. I think the leaves are still better suited for natural or foam products just because of their texture. I think plastic-y leaves would look too rigid, but if you could use the pen to build a trunk in a vertical manner; after painting it may look good. The appearance is similar to FDM 3D printers, but you get the advantage of building vertically instead of in horizontal slices, which would allow you to do more flowing branches. There is no X-Y coordinate system either, which gives you even more freedom. I think the only drawback is the texture. You might be limited with this tool since there is not much else you can make with it. It will be hard to get straight lines, which limits you to scenery items that do not follow a rigid structure.
My thoughts were to use it for trunks and branches. Since it's plastic, a small soldering iron with a narrow tip might be useful for added texture, or just heat up a darning needle or nail. I think it might also work for old wooden fences, occasional rocks or similar.
I've seen some of those in the local electronics shop where I usually get some goodies like fine tools, components, etc. They're also quite affordable. You just need patience and a steady hand when building something up. I might just get one. Great for making tree trunks and branches, especially when you run out of those and you still have loads of foliage left... Now all I need to do is wait until the newest lockdown is lifted.