But that doesn't affect whether we implement the idea separately from LJ (and preferably better).

Regardless, it's an interop problem regardless, as even before they introduced custom heads, linking to a Comm off site still gave the userhead--that's one of the reasons why I set my CSS on my journal to replace the userhead with the pencil icon--I think off site links should use the favicon of the site unless we can easily distinguish between all potential off site types, which we can't and I don't think is worth doing.

For this site, it'd only be an interop problem for other sites running our codebase, nothing to do with LJ.