Salesforce Classic had side panels that could be pulled out when needed and hidden when done.  During usability testing, users had a hard time discovering and opening the side panels.  When Salesforce first released the Lightning update they no longer had the hidden side panels, but by that point users had learned how to find and open the side panels and liked how it allowed them to have more screen space for the client communications.  Recently Salesforce has come up with a method to reintroduce collapsible columns in Lightning.  I created this InVision mockup to get feedback from IBM Support Engineers about whether they would like the ability to collapse the side columns in order to have more room for the client communications.  There was overwhelming support for this option which was even preferred over the two column design that I created based on user feedback in July of 2019.