Hi!
A bit late response on this one maybe, but mapping into a multi-reference property works, if the format of the JSON is as this example:
{
name: “some name”,
materials: [“ID1”, “ID2”]
}
In the above example, you would just need to map materials. I have not tested directly with IDs, but with values of string-enums mapped into a multiref enum property.
PS: There is a bug however on the following: If an appfarm service endpoint returns a data source with multiref property to a “Run Service” action in apps, the value of the multiref property is not transferred. You would need to persist in the service, and read the object in the app.