This came up way back in Stanford. Should a subunit be classified as a type of process. I wasn't a fan at the time - still not, but it kind of makes sense. Also one can include a phenotype as a similar type of non-stiochiometric process. Candiated for inclusion in V2.0.
No. I strongly object to that. This completely breaks the bipartite nature of PD. EPN are continuants, PNs are occurants. And subunits are nothing. Just decorations.