I really liked the original mouse holder, but I didn't like that the hooks are printed directly on the holder itself. So I took the original stl to tinkercad and deleted the hooks in favor of some holes.
To hang this thing on the Skadis, you can use the following hook:
https://www.printables.com/de/model/528977-skadis-universal-hook-without-stick-out
I printed mine on a Bambu Lab P1P with PETG. But you can use whatever you want.
Due to the sticking out part of the hooks, the room for potential mouses may be smaller now than in the original. It's a bit too small for a Logitech MX Master, but mouses like Razer Naga Pro will fit. (added some pictures)
The author remixed this model.