Yeah, in fact only `OrdinationResults` is being used.
Before I added PCoA, all methods worked on a data table (sites x species) and they outputted species scores, site scores, etc. Then came PCoA, which works on a distance matrix and only outputs new coordinates ("object scores"), and I'm not sure how to make it fit in, or if we should even try. What do you think? Maybe there should two different result classes for the two cases, I don't know.