We would propose to have an out of the box way to always add the "?wcmmode=disabled" url slug to urls inside the author "Preview as published" environment because without it, we experience custom components breaking in the "Preview as Published". If it was always added, the author instance's "Preview as Published" could be fully navigateable for an author, which is good for demo's to stakeholders or business or testing UX flows.
An author wishes to test or demonstrate a UX flow to stakeholders on the author's "Preview as Published" to include the most recent visual changes.
An author clicks a link on a "Preview as Published" page and is redirected to the correct URL, but without the "?wcmmode=disabled". The new page features components that visually break, visually misbehave or do not load content from content fragments.
An author clicks a link on a "Preview as Published" page and is redirected to the correct URL, with the "?wcmmode=disabled". All components on the page render well. The author can gets a perfect visual representation of all components, with the latest changes present.
Environment Details (AEM version/service pack, any other specifics if applicable):