EM: modal full screen for information panel
Extension Manager can be configured either to show information using an inline panel or an popup window.
The popup window is shown modally but is quite small. It can be resized and the information is then saved for the particular extension, meaning the new size will be reused next time the information for that particular extension is shown but not for any other extension.
As the window is shown modally, other parts of the Backend cannot be used anyway. Best would be to use a full-screen modal window