How to use blueprint query results as value for a field setting?

Some fields in my blueprint do not make sense when a specific page option is set. I thought about disabling these fields when a condition is met. The condition (in a page method) has the correct string value (true or false) as can I see in the debugging label output.

But how does it work in conjunction with the disabled setting of a field? Currently, the teaser field is always disabled and independent from the redirect value of a page.

My page model:

<?php

Kirby::plugin('rzschoch/page-methods', [
  'pageMethods' => [
    'isRedirectEnabled' => function() {
      return $this->redirect()->toString();
    }
  ]
]);

The blueprint snippet:

type: group
fields:
  teaser:
    type: select
    label: "Mit welchem Element soll die Seite eingeleitet werden? {{ page.isRedirectEnabled }}"
    default: none
    translate: false
    disabled: "{{ page.isRedirectEnabled }}"
    options:
      none: Mit keinem Element
      image: Mit einem Einzelbild
      gallery: Mit einer Bildergalerie

Why don’t you hide the field conditionally using when if it depends on another field value?

https://getkirby.com/docs/guide/blueprints/fields#conditional-fields

type: group
fields:
  teaser:
    type: select
    label: "Mit welchem Element soll die Seite eingeleitet werden? {{ page.isRedirectEnabled }}"
    default: none
    translate: false
    when:
      redirect: false # only show this field when redirect is false
    options:
      none: Mit keinem Element
      image: Mit einem Einzelbild
      gallery: Mit einer Bildergalerie

For me, this only works in parent blueprints (like pages/default.yml), not in section snippets (like sections/page-content.yml). I try to build universal blueprint snippets which decide for themselves what to show.

Your solution would work (but then I always need to adapt the parent blueprint to the extended snippet):

title: Default Page

columns:
  - width: 1/2
    sections:
      pageOptions:
        extends: sections/page-options
        fields:
          pageTitle:
            when:
              redirect: false
      pageContent:
        extends: sections/page-content
        fields:
          teaser:
            when:
              redirect: false
  - width: 1/2
    sections:
      pages:
        extends: sections/pages
      files:
        extends: sections/files

Are dynamic values for other field options than (for example) select field options possible or do they need to be prepared internally?