Vertical side tabs is a very convenient feature.

[995441437]

When opening many PDF files, the sticky note pages become very crowded, making it impossible to see the complete file names.

Perhaps vertical tabs are a good idea.

[junoncannon]

+1 for this feature. You already have lazy loading, so this would be very convenient for research using one too many PDFs.

[GitHubRulesOK]

You can use Favorites in such a fashion if you want (add a toolbar icon)), as thus was around long before tabs, and means you dont need to keep so many open. The major downside is it is a couple of clicks and alphabetic on first character.

[junoncannon]

Just tried favorites for this, and it saves the page, not the PDF. So if you double click, you lose your place, because it goes to the favorited page. Tab behavior is to go to previously opened or last read page in the PDF. So that will not work as a stop gap unfortunately.