If I export my QGIS layout to PDF with "Always export as vectors" checked the resulting PDF appears to render vector data as expected. Line work appears crisp at any zoom level.
Given that the PDF is georeferenced, and contains vector data for the map's features, is there any way to have my map's scale-dependent rendering rules apply in the PDF? I'd like to have some labels only appear as the user zooms in to the PDF. Presumably the resulting PDF would not be compatible with all PDF viewers.