Hairworks creating .apx files in Unity

Hello,

I would like to create Unity Asset for creating and editing .apex files.

I started the asset for another hair solution, but I have fallen in love with the Hairworks.

Are there any legal issues with creating the xml(human readable).apex files or users selling .apex files they create.

Thanks

https://www.youtube.com/watch?v=jdCZEc7W3WQ