Although this was more a wednesday morning comic relief (sorry), I have given some consideration in implementing open reviews. I do not have a concrete user case coming from a journal, but some people involved in the Finnish Open Science project have been interested to hear whether OJS could be used for open reviews. Of course it does support one form of open peer review already.
What I have been thinking about is that maybe OJS could provide a basic functionality for open reviews which could then be extended using plugins (to use for example Hypothes.is). Other thing that should be considered is the identity of the reviewers (I do not think that anyone wants totally anonymous users reviewing papers), so probably Orcid should be involved somehow.
If there are some plans to work on this (maybe in spring sprint?) I would be happy to participate.