@abdulr697

I dont think you can customise to Remove the Case details panel.  there is an option to collapse it but there currently there is no option to remove as. 

As constellation architecture, despite uses Harness, doesnt use sections to render the UI, there is no possibility of customizing it. 

Though not recommended, you can alternatively try to include a custom StyleSheet script that can update the CSS for the div elements on the HTML section with 'display: None' 

This is a long shot approach but no guarantee as it'd be challenging to find the appropriate class name assocaited for the case details item 

@abdulr697

You can't fully remove the preview panel from the Case Detail view in Pega Constellation using built-in settings, but you can collapse it using the toggle. The Constellation design system doesn't allow traditional section-level control like in older UI frameworks, so there's no rule or switch to disable it completely. Some developers try hiding it with custom CSS (like setting display: none on the preview panel's container), but that's not officially supported and may break after Pega updates. If you go that route, you'll need to find the right class or ID using browser dev tools and apply the style carefully. Just know it’s a workaround, not a permanent fix. The safest supported option is to instruct users to collapse the panel manually