While emplacing a pdf, it changes underlying page metadata incorrectly about pikepdf HOT 1 OPEN

I did the following

and results seem to be fine to me, although it looks as if plumber returns position relative to the top left corner rather than bottom left as is conventional for PDF. So it seems fine to me, although perhaps your example is different from your actual code.

OCRmyPDF uses emplace as the primary means of adding OCR text to PDFs, i.e. if it were broken somehow, OCRmyPDF would be failing in most cases too.

If either PDF has structural markup, they won't be preserved by the emplace function, and migrating them unfortunately is quite complicated. QPDF doesn't do that yet but the author intends to implement it, so it will have to wait for that.

from pikepdf.