I have been thinking about this a fair bit and agree that it may make sense to add some extra visuals here, though we have to be very careful about clutter.
I also feel that this is not about “category” it really is about optimising behavior for wiki topics regardless of where they are.
I had a quick look at the implementation which is the reason for this commit PERF: we have no use for topic percent rank · discourse/discourse@7b26f50 · GitHub
I was toying with the idea of adding one more column, but instead now that I think about it, we can just define a “subtype” of wiki.
So, a topic is subtype wiki IF the OP is wiki.
With this info at hand we can attach special behavior and UI at the list level for wiki topics with no extra cost.