In KDE, one can create new Activities, which are a sort of different types of Desktops (sets of workspaces) with specific characteristics:
To specify each activity there are various options.
Clicking the last option of the menu that opens when right-clicking the desktop, one can switch between different 'Layouts':
There a 6 different layouts - each representing a very different type of desktop:
Changing the layout in this way is possible for the Activities that are already in place.
But when you create new activities, there is a different set of options available, called 'Templates'.
One of these is called 'Search and launch': it allows to search (for an application etc) just by starting to type (typing opens the search window) without any other preliminary action like clicking the menu launcher button or using a shortcut to show the search window.
Can this feature be enabled within the main desktop (the default one)?