it’s Dominik from 70:30, creator of Skysane! Skybox Megapack, one of the top paid unity packages in the Textures & Materials/Skies section.
Currently, all sky images are rendered again in better quality, so future updates of the package will replace 1024x1024px images with 2048x2048px until all of the 45 skyboxes are replaced with better images.
Additionally there will be a Skysane HD package with 4096x4096px images for developers who require very high quality for their games - and later Skysane 2 with 45 new skyboxes. For any requests on special skyboxes that you missed in Skysane, please give suggestions to include in Skysane 2.
Currently an update was submitted that updated following skybox packs to 2048: Canyons, Clouds, Phantasm
As some other skyboxes in the package have already been updated, currently around 20% of Skysane are 2048x2048 pixels. The other skyboxes are still in the original resolution, but will be updated as soon as possible.
It is hard to say when all skyboxes will be updated to the better resolution because they are rendered in 4096x4096 which takes very long. Out of these images, the 2048x2048 Skysane images are created and added to the live package.