One solution is to avoid the delay by streaming the PDF as it is personalized, rather than read, personalize, save, wait for 2nd click, save. I've personally used PDFKit .NET 4.0 (https://www.tallcomponents.com/; no, I do not work for them; yes, I have endorsed them because they're products rock) to do just this. That also removes any storage issues that Paizo might have.
Once the PDF is stamped while streaming you'll all be able to right click, download, etc., without that annoying intervening step.
Once that step is gone we could move onto bulk downloading since the personalization is really what's prohibiting that.
Thanks.
(NOTE: The solution above is .NET based. I'm going to wager Paizo is something other than that since they're not reporting ASP.NET or IIS in their headers. So the above component wouldn't work, specifically. But similar components are out there and available for almost every combination.)