Okay, I got irritated at having to jump through hoops to open the Keyboard Maestro Engine log...
The solution? A macro of course.
A Short Press of the keyboard shortcut will open the log in BBEdit (if you have it – if you don't I encourage you to install it and use the freeware version).
A Long Press of the keyboard shortcut will open the log in the macOS Console.app.
Either way the logs folder gets opened in the Finder in the background for quick access to the Editor log if needed.
If you change the keyboard shortcut, be sure to check the Long Press Options and change them too (as necessary).
(See macro below.)
Please note that the Keyboard Maestro log folder may be found in the Help menu of the Keyboard Maestro Editor.
The relevant folder path is ⇢
Note that there are actually two log files available:
~/Library/Logs/Keyboard Maestro/Engine.log ~/Library/Logs/Keyboard Maestro/Editor.log
You will normally want to view the engine log for errors and issues related to running macros.