This article explains the effort involved when upgrading to the latest version of Theme cosmos. Pega 8.6 is released with Theme cosmos. 03.01 version.  

Collapsible case summary panel

Present users with flexible options for reading wide tables and forms in main work area. We’ve added a button to collapse the case summary panel.

Open Cosmos application multiple times in any fashion

Prevent users from losing work or context in one tab/window when they launch the app in other tabs/windows. With this feature enable users can work on multiple session at a time. For more details,please look into the  open-cosmos-application-multiple-times-different-browser-tabs

Search results in new tab 

Present users a way search within the app without losing current context.

Assignment widget in preview panel.

Enable users to easily see and perform assignments directly in preview panel while maintaining list context. For more details, please have a look at preview panel changes migration guide

Support for multiple tabs with scrollbar and item count on tabs.

Enable uses to understand more tab contents and see the full tab name along with counts. For more details please have a look at Multiple tab support

New/Edit modals now size themselves based on content

The modal width will auto resize depends on the content widths. Initally it will maintain the minimum width of the contents which will compact and looks good. For more customisation on this modal,please look into Customize Dialog Container

Automatically render local actions UI in a modal

Per the Cosmos design system, when a case wide action is launched from the preview panel or from within a case, the case wide action UI should always and automatically render in a modal. (The work area is reserved for assignment processing). Also, the actions menu was simplified. This may require app teams to un-override pyWorkCommonActions. For more details please look into Render Local Action in Modal

Improved error banner and success banner styling. 

In a world-class design system such as Cosmos, the style of everything matters, even error/success banners.

Assignment Configuration Change required.

There are changes made to Case Assignments introduced in Theme-Cosmos 03.01 and the document explains the migration steps for your application.Please have a look at Migration of Theme-Cosmos 02.01 to 03.01 - Assignments.