hi @kmatzen/@mallyvai! Adding briefly to Nate's comment (my co-founder at Authorea), I would like to point out that we do support many popular LaTeX packages. One big reason why we do not support custom LaTeX packages is that some of them are really intended for the printed page and cannot be easily ported to the web- and the point of Authorea is to create web-native documents, which render in the browser, first, and can then be ported to print formats. In other words, we support a safe subset of LaTeX which we can easily convert back and forth into other web formats (such as Markdown). Do let us know if you have a LaTeX package in mind and we will see if we can add it for you.