After one installs the above package, the alternative tab behavior is not enabled.
This is because the json metadata for the package has version 3.2.0 while gnome-shell is now at 3.2.1.
I tried setting the version in the json to 3.2, and while that did enable the extension, it badly broke the interface after the first alt-tab was issued.
Keyboard input was ignored apparently, and I needed to click on the logout button to recover.
*** This bug has been marked as a duplicate of bug 739270 ***