If you want a real moat, figure out how to parse existing PDF documentation that is really badly formatted. Think diagrams and tables with text floating in various places, etc. Documentation of this style is very common in industries where physical things are being built in the real world. The standards documentation (IEEE, ANSI, NFPA, etc) doesn’t usually parse cleanly, much less the messier internal documentation within the businesses.
Grobid is the best example of such a documentation parser, but it is so laser focused on academic papers that it fails to properly process industry-style standards and SOP documentation. What the world needs right now is a Grobid that works for other kinds of messy documentation.