Can I only deactivate certain users?

With version 1.2 you can now alter the expiration date of a specific user during authentication user a filter.

add_filter('uae_expiration_date', 'ddc360_alter_expiration_date);
function ddc360_alter_expiration_date($expiration_date, $user) {
    $users_to_restrict( 1, 2, 3, 6);
    if(in_array($user->ID, $users_to_restrict)) {
        $expiration_date = 123456;  //registration date +1
    }

    return $expiration_date;
}