Some new information
Creative Tim has new bootstrap5 themes and of course, I was curious. I almost bought a developer license again, but then I checked their license policy. I am sure that when I bought Gaia and others (I don't think I used them, maybe denice theme was available for free), there was a different developer license available.
Now they separated it into company and enterprise licenses and formerly developer is now called a company license.
With developer license I can't :
I can't create a free theme! You can do this with themeforest themes with a single license, so imagine my surprise. Of course, I didn't buy the new bundle. But I asked them to upgrade my old bundle and they kindly give me one freelancer license for testing and learning. It means that I will do themes only for myself.
What about old developer licenses?
It means all Gaia or Hestia themes are all right. If you stole it, it is your problem.
Again, it is their policy and they deserve any penny that they want. Their themes are very good and they helped me to learn how to use sass. And again, they give me a license for personal use for free.
But it means that there is no point in developing new themes with their free version (I hope that they are GPL licensed, I didn't check it).
I am glad that I let remove my themes from e107.org and now I need to clean my GitHub repos.
Thank you to all that helped me with Gaia and Hestia. For bootstrap3 and bootstrap4 themes I still have the developer license, but I can't give them for free.
This is the original license for all my former themes:
So I was right, it was totally different then and so here is no problem with Gaia and other themes.
The code inside head tags
Custom theme shortcodes