Update webhook with multiple entities

In https://developer.copper.com/webhooks/overview.html#multi-event-notifications it suggests that multiple entities might be in a single json body, and ‘ids’ is an array.

If e.g. person-1 has field A updated, and person-2 has field B updated, what will be shown in the response?

E.g. below, what wil i see in updated_attributes, will 633516 have 4 entries, e.g. ‘null’, ‘new’, ‘null’,’null’?

how would i figure out which id in the top list corresponds to which entries in the bottom updated dict?

{
  "secret": "secsrc",
  "key": "seckey",
  "subscription_id": 329052,
  "event": "update",
  "type": "person",
  "ids": [
    137998516
  ],
  "updated_attributes": {
    "custom_fields": {
      "633516": [
        null,
        "don-test-sequence"
      ]
    }
  },
  "timestamp": "2024-02-04T16:26:03.836Z"
}