Like everyone else, I am absolutely thrilled about the beta, and can't wait to see how it develops.
One of the key reasons to use LaTeX or InDesign over Microsoft Word is their superior type composition. While Word simply dumps in text as it occurs, without regard to spacing or line breaks, these other programs look at an entire paragraph to remove rivers of type, reduce the need for hyphenation, and so forth, just as human type compositors do. In TeX, this is the Knuth-Plass Line Breaking Algorithm; InDesign has the Adobe Paragraph Composer (which it uses by default, but also has an option to turn this off with a single-line composer). Implementing this in Affinity Publisher would make it far easier to produce professionally typeset documents.