The following 4 properties are available for PXSelector and PXSegmentMask input controls to define size range for a drop-down window:
Please be advised, the 4 properties listed above are hidden from the Properties window and won't be suggested to you by IntelliSense while editing Aspx pages in Visual Studio.
Default 13-column layout defined for the Customer selector on the Sales Orders screen (SO.30.10.00) doesn't quite fit the default size range specified for selector drop-down window. To help users explore as much information as possible and save their time on scrolling horizontally to see all of the columns, you need to increase the maximum drop-down control width by assigning a bigger number to the MaxDropWidth property of for the Customer selector.
To set value for the MaxDropWidth property in Layout Editor, uncheck Hide Advanced Properties radio button as shown on the screenshot below:
After publishing the customization, users can enjoy the new layout of Customer selector, now expanded upon entire working frame: