Flat ports v W/A ports for macro?

For those of you who have both wide angle dome ports as well as flat ports on your video rigs, I was wondering if you noticed any benefit when shooting macro when using the flat port.

With the Phenom and their WA port, it has full zoom through, but I am not sure the theorectical magnification I anecdotally hear about manifests itself in switching to a flat port.

It might be nice to have one as a backup, especially if it magnifies the subject over my WA port. So far after over 100 video dives I have not yet managed to scratch my Phenom dome port on anything, coral or otherwise.