Content Flow Routers with Multi-Instance Flows

I've built flows for a 940, 943, and 856 inbound that is piped into Camelot 3PL Software's Excalibur WMS. I was curious whether I could route all that EDI traffic through a single Multi-Instance flow. The thought process is that the Export would be the same with different parsing. The Transform would check to see what kind of document you're working with and convert it to the API format needed for Excalibur and then send the API call. Where I got stuck is that I'm not sure how I would specify the instance in the content flow router.

would i change

flow_id: ABECD
export_id:ebcd

to

flow_id: ABECD
instance_id: 12t2d

Would you change the directory or file criteria you're looking for on each instance? If so, you should be able to override the export doc with something like this. The abstract ID would be your abstract flow export ID that is being overridden; then you'd use whatever file definition needs to be overridden, along with any file directory or filters.

{
  "exports": [
    {
      "_abstractId": "6983d668c0cf4ff9184a75be",
      "file": {
        "fileDefinition": {
          "_fileDefinitionId": "6983d667127f9c63c5ba750f"
        }
      },
      "filter": {
        "type": "expression",
        "expression": {
          "version": "1",
          "rules": [
            "contains",
            [
              "string",
              [
                "extract",
                "filename"
              ]
            ],
            "950"
          ]
        },
        "rules": [
          "contains",
          [
            "string",
            [
              "extract",
              "filename"
            ]
          ],
          "950"
        ],
        "version": "1"
      },
      "ftp": {
        "directoryPath": "/"
      }
    }
  ]
}