Exported PDF size - still way too big / resizing (split)

[Audsvisual]

(split by mod from this related thread )

New to Affinity Publisher - 5 page document for web viewing + embedded small file images (see below) Doc set up (see below image) and the calculating exporting to PDF small digital size is taking far too long. I have to choose PDF (flattened) for the document to export. Resulting in light grey lines around the images. I have tried to follow members thread on the same problem with no avail. Please help - this is for a client. [1.8.6 version on macOS Mojave 10.14.6]

[Callum]

Hi Audsvisual, 

I'm confused as to the nature of your problem as the title of this thread states that the exported file is too big however your paragraph seems to say its just taking too long to export. Which of these problems is the case with your file? How long typically does the file take to export?

Thanks

Callum

[AlanPickup]

I recently posted in the Apub Beta forum about simmilar problems which I have again experienced in the retail version. I have just created a 3 page publication with 27 images embedded over 3 pages of A4. I have used 29 picture frames approx 63x63 mm I have then used windows smipping tool to copy the middle of 27 A4 flyers preciously created in Publisher. I have them inserted them in to the picutre frames using replace image  and adjusted to fill the frame. The images are between 50kb to 140kb I get a file size of 27.1mb. Exported as a pdf at the setting below I get a very large file size of 29mb. If I then import the pdf in to Apub the file size is 18.6mb when exported as a pdf on the settings below the pdf is 2.98mb. As these are for emailing or downloading the 27mb pdf would be useless. I am by no means an expert on pdfs so any help would be gratefully  received. If you want the files please send a link to upload.