Thank you for the great explanation. It would be great if you could add the content size adjustment option to the calendar and news feed tiles in a future release, in the meantime I will try and fool around with the custom CSS approach when time permits.
Hey quick update for anyone else that runs into this. I reviewed the post on List of working CSS code that Josh posted above and that method is super quick and easy just go to Configuration - Edit Theme and add the following custom CSS into the Custom CSS section at the bottom. This font size brought me back to where I was prior to the scalable feature.
.tile.calendar.agenda .main-content { font-size: 1.75em; }
.tile.news-feed .main-content { font-size: 1.75em; }
Thanks again Josh and James,
Spencer