Can you post to board-level discussion via API?

Hi everyone,

I'm trying to post to a board's discussion section (not item-level updates) using the API. I can successfully read board-level updates using:

query {
  boards(ids: [YOUR_BOARD_ID]) {
    updates(limit: 25, page: 1) {
      id
      body
      creator { id name }
    }
  }
}

However when trying to write, the create_update mutation only seems to support item_id — there's no board_id argument (confirmed via the playground autocomplete).

Is there any workaround for posting to board-level discussion via the API? Or is this simply not supported as a write operation?

Thanks!