The issue I had with all the stands I found is lack of support and weight when paired with the 3D printed Mynt3D Spool (https://www.thingiverse.com/thing:4446373). With the spool, it was too heavy, and the pen would tip over. I took this stand (The file I started with: https://www.thingiverse.com/thing:5747642) and added a hollow base, so I can fill it with weights. You can put whatever you want inside it to make it heavy enough to support the Mynt3D Pen. In my case I used wheel weights, but other options could be rocks, sand, dirt, puddy and etc. As you can see, with wheel weights, I was able to get my stand to weight about 15oz (424g), and that is more than enough to keep the 3D Pen nice and stable.

After you fill it with goodies, I glue the 2 halves together (I used E6000 adhesive). Keep in mind the 2 parts has a tight fit, so you might need to use some force to attach them.