It seems like the author wants to prevent commercial use of the software:
> I want this project to be as widely accessible as possible, while still funding the development costs. This project is completely free for non-commercial and personal usage. Commercial usage is restricted via a license. Feel free to contact me if you want to license this commercially
You're not permitted to use the tool to migrate your commercial blog. This is why BY-NC is not considered a free license in the most common definition of the term.
However, this license does not apply to the generated output. It only applies to the work the license is attached to. It's not a viral license in that sense. You can migrate your blog and later turn it into a commercial enterprise without risking copyright violations.
If you want to migrate your commercial blog, you should ask the author. They can license their code under any license they choose, so they could sell or give you a copy licensed such that you are legally permitted to use it commercially.
It seems like the author wants to prevent commercial use of the software:
> I want this project to be as widely accessible as possible, while still funding the development costs. This project is completely free for non-commercial and personal usage. Commercial usage is restricted via a license. Feel free to contact me if you want to license this commercially
You're not permitted to use the tool to migrate your commercial blog. This is why BY-NC is not considered a free license in the most common definition of the term.
However, this license does not apply to the generated output. It only applies to the work the license is attached to. It's not a viral license in that sense. You can migrate your blog and later turn it into a commercial enterprise without risking copyright violations.
If you want to migrate your commercial blog, you should ask the author. They can license their code under any license they choose, so they could sell or give you a copy licensed such that you are legally permitted to use it commercially.