[laen]

Can you elaborate on how you parse the PDF? Are you simply converting it to text using a python library or something more robust like GROBID[1]?

1: https://github.com/kermitt2/grobid

[airbreather]

Do you know of anything that can process engineering drawings and diagrams by looking how lines link text and other objects?

[malshe]

Not the OP but I that's what I do.