Yes, the tool I’m describing works on what the pdf_oxide crate returns, which includes glyph positions.

Here’s a public appendix from a recent Federal Circuit case. It has a representative assortment of documents (opinions, briefs, patents, transcripts) but contains only cited pages to the appendix pagination is non-consecutive: https://www.courtlistener.com/docket/68048163/15/ecofactor-i...

The underlying docket is usually 100 to 1,000 times larger than this but it’s similar types of files and the appendix shows the various types of headers and footers that can exist.