Data Commons have been using /Observation heavily, and @darobin has also been looking into using it (see https://gist.github.com/darobin/07324754f0db7f090d737b9d2616536c). The /Observation type is in "Pending" status currently which means we are looking for feedback. This issue is to make some updates based on implementor experience.