There was a pitch from @taylorswift that I expect the documentation workgroup would be interested in discussing:
In particular:
Currently, developers such as myself are in a difficult position where we would obviously like to support the advanced linking features of Taylor's swift-unidoc engine. However, given DocC's weight in the ecosystem (it is included in the toolchain and powers Xcode documentation), in case of any future divergence, we would need to prioritise DocC's way of doing things.
I don't have an opinion on the technical details of the link format. I think it's great that members of the community such as @taylorswift care so much about improving Swift's documentation tooling (it has clearly been a large time commitment), and I also think this should not be a competitive feature -- that package developers shouldn't have to worry about incompatible link formats. But that's as far as my opinion goes. I'd just like to encourage everybody involved to work something out.