This addon allows you to exclude artworks of specific users from showing up in Recommendations section as well as tag pages by adding said users to a blacklist. Their artworks will be simply hidden. The addon will display a counter to show how many artworks it removed. Additional functions

Exclude the artworks of the author on who's page you are currently on from the Recommendations.
Restore proper uncropped artwork thumbnails, in their original aspect ratio.
Limit the number of recommendations shown.

Usage instructions:

Clicking the addon icon on the toolbar opens the addon's Options page
To add a user to a blacklist, right click a link to a user's profile, which would be in a format like "www.pixiv.net/en/users/<user_ID>", go to "Pixiv User Filter" -> "Add User to Blacklist". Removing a user from blacklist can be done in a similar way, just choose the option "Remove User from Blacklist" instead.
Another way to add/remove users to a blacklist is to edit it directly in the addon's Options page, by manually adding/removing the user ID(s). The format of the list is each user ID on a new line. Click Save button to save the changes.
You can see how many artworks were removed either above the artwork grid to the right of the grid header, or on the addon icon on the toolbar, assuming the addon icon is pinned.
If you also want to remove the artworks of the user who's artwork you are viewing currently from its Recommendations section, check the appropriate checkbox in addon's Options page.
"Restore proper uncropped thumbnails" allows you to uncrop the thumbnails and display them in full, in original aspect ratio. Idea from the "Improve Pixiv thumbnails" userscript.
"Limit the number of recommendations" - does just that. By default Pixiv loads up to 180 recommendations in batches of 18, slider is also divided by increments of 18 images to match that. Can set 0 to block all recommendations. Using this option not just hides recommendations but blocks loading requests entirely, so blocked images won't be loaded at all.
Export Blacklist button allows you to quickly save the current blacklist as a .txt file, for backup.

Bugs / Issues / Suggestions Can be reported / posted on GitHub Known issues:

On non-English search/tag pages the inline removed artworks counter won't be shown. Its an intentional limitation, as I simply haven't found any good way to place it without relying on the header text yet.

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