Is it possible to get a default meta field like the post type page's Featured Image (key: _thumbnail_id) to show its thumbnail version in the admin columns without modifying how the existing meta field works? If so, what would the code look like? I was able to get the key _wp_page_template to work using the type 'text', but using the type 'single_image' or other types did not work.
Scratch that, the key _wp_page_template isn't working either using the type ‘text’ since it uses a select element with options populated based on the existence of page theme template files. Is it possible to get existing meta like this to show as page admin columns without modifying the existing fields?
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