@nebulon I am not a programmer/developer so I am unfortunately not in a position to contribute to the code. However I am more than happy to help with testing as well as sponsor the development of new features! 🙂
With regards to the subject of this thread, it seems that one option for OCR would be to use OCRmyPDF and a search engine such as Solr or Elasticsearch.
I'm sure there must be someone with experience in these areas lurking in our community! 😄
At the end of the day, I think we all want a secure, simple, reliable, file storage & sharing solution with a robust search engine so that we can easily find what we are looking for. Self-hosted & FOSS ofcourse!