How to enable omit_empty_optional_fields?

[bbjay]

I'm trying to get omit_empty_optional_fields: true working, but im unsure where to put it or if there's some limitation.
What I have tried so far is putting this:

output:
  omit_empty_optional_fields: true

basically on every level from config root to fields.

I have the following in my collections:

  collections:
    - name: "about"
      label: "About"
      i18n: true
      files:
        - label: "About Page"
          name: "content"
          file: "content/{{locale}}/about.md"
          i18n: true
          fields:
            - {label: Title, name: title, widget: string, i18n: true}
            - {label: Slug, name: slug, widget: string, i18n: true, required: false}
            - {label: Test, name: test, widget: string, required: false}
            - label: Main
              name: main
              required: false
              i18n: true
              widget: "object"
              fields:
                - { label: "Display Name", name: "name", widget: "string", i18n: true, required: false }
            - {label: Body, name: body, widget: markdown, i18n: true}

What I get as output in about.md is

---
title: About
slug: about
test: ''
main: null
---
Hello

But I expect it to be

---
title: About
slug: about
---
Hello

with the empty required: false fields omitted.
The main field is not there when left empty on first save, but adding and removing it again leaves it with main: null.

Am I missing something?

[kyoshino]

Will check why it’s not working.