Here's a dump of what I have in my mind for the site in the future, in no particular order or timeframe.
Versus. Compare two features to see which one has better support. (For example bgcolor HTML attribute versus background-color CSS property.) I started working on the front-end presentation in the versus branch, but this still needs a lot more work.
Recipe. Concatenate multiple features and see support for them altogether. Using a + in the search field already allows to see multiple unrelated features, we now need to add a summary for support of them all. As of september 2020, the + combinator works (example). I now need to add overall support stats for the selected features combined.
Documentation. Improve every aspect of the documentation to increase contributions and feedbacks.