By the way, for the ones of you who own a second screen and wanna have an easy way to handle the different PDFs I can recommend the ChartViewer application.
That app originally was designed to manage airport charts but basically you can organize all of your pdfs and easily open and look at them.
The pdfs are managed in a folder, subfolders do appear in the open application as on the disk.
I attached a png with a screenshot. If you wanna download the app - google; it is free.
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