After expanding the view of an item from the detail drawer to the full view, there should be a corresponding CTA (call to action) to collapse the detail view back down to the drawer view. I understand that I can click the back button to achieve this but that's not at all intuitive. Perhaps an impediment to adding the "collapse" button is that their may be no where to go if the item was opened from a link to the item and not from a detail drawer view. Putting this idea into the Ideas category knowing that it actually applies to several categories.
Thank you for the request. As you describer, a blocker of a "collapse" button is that there isn't a place to go since the drawer view appears "on top" of an actual page (vs. a standalone page).
With this in mind, along with the workaround with the "back" button, we're unlikely to make updates in this specific area. We hope you can understand.