Typefitter 5 Professional will not only recommend fixes for common typographic issues, but it will automatically fix them using its powerful automated copy fitting rules. Typefitter Profiles (the successor to Typefitter 4's Typefit Styles) and the Fix & Find and Fix All buttons are Typefitter 5 Professional features that are disabled in Typefitter 5 Standard. In addition to these features, Typefitter 5 Professional will support InDesign scripting for even more powerful and flexible automation (*requires the Scripting add-on). When Typefitter 5.1 Professional is released later this year, current Typefitter 4 subscribers (prior to 1 June 2021) will receive a coupon for a free upgrade to Typefitter 5.1 Professional.
For a comprehensive feature comparison between Typefitter 5 Standard and Typefitter 5 Professional, see Typefitter 5 editions.