The platform installer uses a file name for the CDK box with no version information making it difficult to tell if you have the latest CDK box or not.

The downloaded box file is saved in \cdk\boxes\rhel-vagrant-virtualbox.box.

It should use the same file name as the Red Hat Customer Portal to make it easy to identify that it is the same file: rhel-cdk-kubernetes-7.2-23.x86_64.vagrant-virtualbox.box