Changed WRT to when? There have been several updates to the Command Center since its introduction. One of them was the addition of a verbose install option which essentially runs the installers as if they were run from the command line. There are also settings for VST2 32 bit and 64bit installation paths, a setting for the path to the installer cache and Cakewalk Content.
Still the Command Center uses the same installers available in the store account. AFAIK, the DPro installer has always contained both 32bit and 64bit binaries and a prompt at the beginning of the installation process to select which one to install.