Formatting logs in OS X Console
Check out this article:
https://developer.apple.com/library/mac/documentation/MacOSX/Conceptual/BPSystemStartup/Chapters/LoggingErrorsAndWarnings.html

It looks like there isn't any way to nicely format JSON for the console app, but you might be able to use the tagging system for some increased clarity.

Probably a better idea to include instructions on how to open the log in a more capable program.