I downloaded this fork of tumblr-utils yesterday (June 10, 2024) and comparing the media resolution with Tumblthree's downloaded files, this one is much smaller.

I downloaded a blog using the basic tumblr-backup blog-name command, and looking at the media files, an image was only 640x640 while on TumblThree it downloaded the image as 1024x1024. I haven't tried it out on gifs and videos yet, so I'm not sure what resolution they download as. Is there any way to always download the best possible resolution for the media?