Thanks for the rating, glad you like it.

Your feature requests are kinda asking for a lot though. Detecting duplicates is way out of scope for a simple addon, trying to find linked bigger versions of an image is a logistical nightmare while a user can do it himself easily, and downloading all in an area is a very tricky thing to do. Determining the "pattern" will often not have the result users want either and will be heavily affected by every individual website's structure.

I get the feeling one of your underlying problems can be solved another way: I use my other addon Copy Selected Links to get the full-res links of images in a thumbnail gallery, and throw them into jdownloader or similar programs to get all the full-size pics. Maybe that solves one of your problems?

This might also interest you: https://gitlab.com/Marnes/doubleclick-image-downloader/issues/35