I'm partly sad at the approach this and other engines take: reimplement each part (PDF parser, etc etc) in a way where they are pretty much useless except in their specific engine.

If instead we had a PDF() class that did what RAGFlow is doing (dealing with all the different trade-offs of the different python PDF engines such as pdfplumber), then we could easily adapt it and improve it, and it can be useful for other projects as well.