CorvusC

This is definitely problematic. InDesign has a preference for this behaviour: "Skip by leading", so you can at least turn it off there. It seems counterintuitive to have text jump round an object and behave as if there were invisible lines of text in between, unless you're using a baseline grid. Obviously that's what would happen if text was wrapping to one or both sides of the object, but I strongly suspect that most of the time people use the "Jump" wrap setting they want the text to continue straight after the wrapped object.

PDFs exported from Publisher that contain multiple copies of placed PDFs (e.g. a logo appearing on every page) contain a copy of the place PDF for every occurrence in the document. The expected behaviour would be for the placed file to be included only once and referenced wherever it occurs. The colour space information in a simple vector PDF takes up far more space than the image data and quickly creates a very large file (I produced a 17-page document which, on export, was over 18MB. Acrobat's Audit Space Usage showed that 15MB of this was accounted for by colour spaces. Using Acrobat's optimize function to discard objects and user data and clean up the file got rid of these, and left a 3MB file without any recompression of the images).
Acrobat's Preflight inventory feature shows the multiple copies of the placed PDFs. However, this only happens with PDFs that are linked in the Publisher document, or PDFs that are embedded but the source PDF is still available in its original location. Moving the source file for the placed PDF to the trash immediately results in a reduction of the estimated file size in the export dialog, and Acrobat's inventory shows only one copy of it in the resulting PDF.
To reproduce: open the attached .afpub file. It includes the linked Logo.pdf on a master page, and has two pages based on that master. Start an export with the standard "PDF (for print)" preset - you will see the estimated file size to be around 966kB (you may need to change the PDF Passthrough setting in the Preflight profile to PDF 1.5 for it to export correctly). Create another page based on the same master and start the export again - the file size estimate will increase to around 1.4MB. Change the linked file to embedded in resource manager and export again - same size. Now delete or the logo PDF file - the exported file reduces to about 550kB, as it has only one copy of the passed-through logo, which would be the expected behaviour.
Affinity Publisher 1.9.0, Mac os 10.12.6, MacBook Pro 15" (2016)
PDF passthrough test.afpub Logo.pdf