PATCH /api/v2/conversations/voice/{id} queue transfer returning 400

Problem

How do you actually patch a voice conversation to swap the queue without dropping the call? I’m hitting /api/v2/conversations/voice/{id} with this payload but it just bounces back with a 400 Bad Request.

{
 "queueId": "a8b9c0d1-2345-6789-abcd-ef0123456789",
 "transferType": "blind"
}

Error

The genesyscloud.conversations.update_conversation method doesn’t handle queue transfers anyway. The 400 response complains about a missing transferRequest wrapper but the endpoint docs skip the nested structure, so I’m stuck guessing the keys.