I am running Photo Mechanic version 5.0 13217
Mac OS X 10.6.8
The text watermark feature has the option to select the font panel. I spoke to your tech support, Brandon, a few days ago regarding this matter and he had the same issue.
Attempting to change the size of the text water mark using the font panel does not work, it will not alter the size of the text watermark no matter what combination of selecting the text and selecting the size option or the order and/or closing the font panel box.
And while thinking about this- the text watermark reduces in size with portrait oriented photos- is there a method to keeping this all the same size on every photo?