Hello,
I have forwarded your request to the Stardock Support Team for their review and recommendations. Please keep an eye on this thread for any updates. We really do appreciate your feedback, Thanks

Basj,
Stardock Community Assistant.

I think you misunderstood my question. I'm asking if Deskscapes will support WebP in the future. I'm not looking to convert images to the file formats Deskscapes already supports.

It's all good. I prefer the newer WebP format. It's smaller in comparison to a JPG, the compression algorithm in WebP is superior in my opinion without any loss of quality, compare a WebP image to a PNG and it's identical at a much smaller file size. I have a big collection of wallpapers from 4k to 1440p, and when I converted the original files from JPG or PNG, the difference in storage space used by JPG/PNG to WebP decreased considerably. 

Unfortunately, WebP is technically a web format to reduce loading of raster graphics. Because of its high compression and its ability for transparency, Google made it to essentially replace JPG, PNG & GIFs on the web, making websites load their images faster. I've been using it for wallpaper management because Display Fusion supports it. Unfortunately, Display Fusion is a big resource drain despite it's many features.