Asciidoc autonumbering callouts with modified start number

Question

I'm currently using Asciidoc to document a YAML code snippet with auto-numbered callouts. The problem I'm having is I'd like to start the callouts at "2" instead of the default "1". This would allow me to reuse the first callout throughout the snippet, since this doesn't work for auto-numbering. I'm able to start the callout descriptions by adding [start=2] but can't seem to get that to work in the code snippet.

Here's an example:

[source,yaml, start=2]
----
apiVersion: v1
baseDomain: example.com <1>
controlPlane: <.>
  hyperthreading: Enabled <.> <.>
  name: master
  platform:
    azure:
      osDisk: <1>
        diskSizeGB: 1024 <.>
      type: Standard_D8s_v3
  replicas: 3
  azureVar: 78 <.>
  test: z <.>
----
[start=2]
<1> baseDomain and osDisk
<.> controlPlane
<.> h1
<.> h2
<.> diskSizeGB
<.> Gov
<.> test

I've attached the screenshot of rendered HTML below: You can see the controlPlane code callout starting at "1" instead of the preferred "2", whereas the callout description worked as expected. Any idea if this is possible?