Upgrade
To upgrade from an earlier installation execute the following in a terminal:
sudo apt-key del 78BD65473CB3BD13
sudo apt-key del 93C4A3FD7BB9C367
Now you should be able to install the current version via the regular command:
bash -c "$(curl -fsSL https://raw.githubusercontent.com/perguth/chromeos-developer-setup/master/setup.sh)"
The smart card now works right away. No more extra terminal steps needed after plugging the card in.