Discovered from a Derpibooru thread, since DA has changed their image links, it's now possible to obtain a larger resulution than what is openly available for download. Take this link:
The image is 600x749. If you delete everything from /v1/fill onwards, you'll get this:
Which is 2192x2735, closer to the full resolution of 2950×3680. This only gives images up to a certain dimension, which means absurdres images won't be able to be obtained in their full size, but it's better than nothing I suppose. I'm not sure if this was already discussed here.
Updated by Alien Fluff