The solutions that I have found seem to involve recreating the PDF. I am not the author. Is there anything that can be done to sidestep this flattening? If possible, without a saving-as to a new file because the original document is part of an email attachment that I want to keep as-is for documentation purposes. But if I have to save-as, that's better than waiting half the day for the flattening.
Afternote: Saving as small/compressed PDF doesn't help either. This is frustrating. PDFs have established themselves as robust read-only documents, but to not be able to print....I long for the simple days.