Yeah… I saw some of that in my short review, but think it may not be necessary. With Dgraph, everything is edge based natively so finding edges is simply traversing a graph. I would think that the examples and Hasura show one way that it can be supported but Relay docs lead me to believe there are other ways to support the same functionality.
*Still looking for someone who has done it before Relay w/Dgraph, but will probably be Monday before I get responses.