Issue: Graphic sizes
You may find some figure heavy (charts, grafts) pdf files will be difficult to work with because they take a long time to open or as you scroll between pages, take a long time to resolve each page.
One reason for this would be high-resolution images.
How to Fix: Acrobat Tool
1) Ensure the document is converted with the highest-resolution possible for the images - At least 600, flattened.
2) Open the file in Acrobat Professional.
3) Open the Print Production panel (found under Tools). The panel does not display by default. You may need to select Print Production from the menu (upper right).
4) In the Print Production panel, select the Flattener Preview.
5) Select Flatten.
Critical Key Action:
ONLY perform this action on one page at a time.
If you attempt several pages at once or the entire document,
the tag tree will drop tags.