Most objects in SAP ERP can be double clicked to get more information in the same window.
Is it possible to open that information in a new window (mode) without replacing your current one?
The double click is an event like many others, and whatever happens whenever you double-click somewhere was programmed by whoever wrote the application. So unless that person or group of persons specified a way to open a new window through some kind of application-specific settings, it won't be possible to always open a new mode. There is no system-wide switch or per-user-setting or something like this.