I did something similar with the Path of Exile cosmetics shop so that I could better find matching microtransactions for the set I was trying to build.
In both cases, I reached out to the official devs to offer to help just make their official one better, but both rejected my offer. So I ended up just building them for my own use.
------
Unrelated, there was a popular hiking trail I liked that didn't have a good map. I made one by combining several sources and formatted it into a PDF. I submitted it to a local trail group. Within a few months it became used and shared widely, which I didn't realize until a friend of mine printed it out and invited me on a hike. "Check out this great map," he said, "it's finally clear where the trail is". We had a laugh when he discovered I made it.