Hello, I'm the main dev for the badge design tool. It took around 2 weeks to go from concept to sketch to the MVP you see today. It was released to the public just yesterday, which is why it has a few niggles. I did limited testing for a number of reasons:
1 - I'm lazy
2 - I think I'm a great programmer, moi? bugs?
3 - It's not mission critical (that's the real reason)
I'll address any bugs or issues and push them as I do. The tool sits outside of our main certification platform and any feedback will help us refine it before we add it to the platform.