Hi Michael Hart,
The Pro version is going to update this week with lots of improvements and regarding the updates difference between lite and pro theme, the reason is that the pro theme is tested through various purpose and doesn’t contain bugs where as we found small errors on the free theme so we updated it.
The process of updating the pro theme can be found on this link. https://www.styledthemes.com/wordpress-tutorials/410-installing-updating-themes
Thanks
