The third beta for Mac is available for download from the link below:
You can change the font by adding the following lines to the file ".adom.cfg" (located in the directory ".adom.data"):
Font_Name = Courier
Font_Size = 15
These are the default values. You can replace the font with another fixed width font (e.g. Courier New, Monaco) and change the font size. Don't use a proportional font.