Hey that's pretty cool!
For the log files check the File menu, there's an option in there: "View Log Files" to get to the log files folder. Just keep in mind that after PixelCNC crashes and you launch it again the newest log file will be of the instance of PixelCNC that you're running at that moment while the one before that will be from the instance that the crash occurred during. So, the second-to-last, if you get to the PixelCNC log files by running it again after a crash and going to the File menu.
Also, when you intentionally invoke a crash be sure to enable logging of debug information from the config menu beforehand. It will have the log file be outputted with the most information possible. Just check to ensure that it's disabled afterward when you continue using PixelCNC or it can severely bog down performance due to all kinds of extraneous bits of information about program state being output to disk during computationally-intensive functions like updating the canvas state and generating operations' toolpaths.