Simon 5 is coming soon!
Simon version 5 is currently in beta testing. It is a massive update, introducing a much-requested feature: syncing the Simon data between multiple Macs, plus a Simon Status service, a Link Checker filter, improved Find filter, iMessage and Speak Error notifiers, a new app icon, and much more.
Important: please note that Simon 5 requires a minimum of macOS 10.12 (Sierra), and will be a paid upgrade from Simon 4 after the beta. Purchasers since September 1, 2020 automatically get a version 5 license (that also works in previous versions).
Re: Feature request: change details
In Leopard, you can point to a line to see the full text of the column in a column expansion box.
You can also select one or more lines and copy them to the clipboard, then paste into TextEdit or elsewhere to see the full content.
You can compare before and after by looking at two lines.
However, I am thinking about adding an option of double-clicking a line to show more detail, perhaps in a separate window or sheet.
Copy for changes would do
Copy for changes would do for now, but a "before-and-after" comparison on a double click would be fantastic!