I find it absolutely ridiculous that Trello would take away the ticket collapse and color feature. My team moved to Trello less than a month ago, and it has become one of our favorite features - the ability to collapse tickets helped me better compartmentalize which tickets to focus on, and the color coding helped us visualize urgency.
The removal of these features does not make any sense, and I would like to request that the Trello team bring back those features and also include them on mobile.