For years I've run FMPA on my desktop machine exclusively. I recently acquired a MacBook Pro (from my daughter when I bought her a newer one). Today I installed FMPA on the laptop from the version 13 upgrade disk image. All that was required was the license key. Had the installer asked for an upgradable previous version (12), I would have pointed it to the installation on my desktop, but it didn't ask. As long as only one computer has the program running at a given moment I believe I am in compliance with the EULA. Since all my machines are on the same network FM would know that more than one instance of the program was in use. Of course, when the two machines are not on the network (laptop not at home) the point is moot.
Thanks Rick. You helped confirm what I had assumed,