GNOME Shell Gets macOS-Like Ability To Close Apps From The Alt-Tab Switcher
Since May 2010 has been Bug #620106 requesting GNOME have the ability to close applications during the alt-tab switching process, similar to what MacOS X provided and continues to offer. After years of inactivity, the bug report was recently reignited and now in time for GNOME Shell 3.28 there is this capability.
There is now a shortcut to quit an application while alt-tab switching via the Alt - Q key sequence.
And another commit providing more functionality, "Similar to what has been done for the apps switcher, this allows closing windows pressing W or F4 while operating the windows switcher popup or the apps switcher popup while navigating the list of windows for an app."
This GNOME Shell addition will be present for next month's GNOME 3.28.0 release.