How to merge TOC of MDC components back into the parent?

[adrianrudnik]

For a small multi-lingual page I would love to use MDC for shared headlines / sections, something like

# doc title

::description
some text
::

similar to the one mentioned in https://content.nuxt.com/docs/components/slot#named-slots, while having a MDC like

<template>
  <div class="doc-description">
    <h2>{{ t('doc.description') }}</h2>
    <slot />
  </div>
</template>

While the MDC seems to produce a toc element within the ast, it does not seem to be merged back to the page, so the translated h2 will be missing from the rendered TOC.

I've tried all ways I could think of, like this Example.vue MDC:

<template>
  <h2>Test: H2</h2>
  <ProseH2>Test: ProseH2</ProseH2>
  <MDCRenderer :body="ast.body" :data="ast.data" />
  <MDC :value="md" />

  <MDCSlot />

  <pre>{{ ast }}</pre>
</template>

<script setup lang="ts">
import { parseMarkdown } from '@nuxtjs/mdc/runtime'

const { data: ast } = await useAsyncData('markdown', () => parseMarkdown(`
## Test MDCRenderer H2
### Test MDCRenderer H3 1
<h3>Test MDCRenderer H3 2</h3>
`))

const md = '## Test MDC'
</script>

with an example markdown file of

::example
## Test: Markdown
::

but only the ## Test: Markdown gets inserted into the pages final TOC, while the ast clearly shows that all TOCs have been detected properly.

Is this just not supported or am I having a configuration error or doing it just wrong?