I think that I am getting closer to a version of LockRattler which includes all its new extended features, but which applies them better across all three versions of macOS.

Version 4.1b3 includes two improvements for El Capitan:

• The command used to Check for security updates should work at last, rather than resulting in an error.
• LockRattler now checks at the outset which version of macOS is running. If it is El Capitan, it does not display information about the Gatekeeper Disk protection, which was only introduced in Sierra. That information is similarly omitted from the text report.

For all versions of macOS, if LockRattler cannot find an update for a specific tool, it now says so, rather then returning an impossibly old time and date.

I stress two important points in the updated documentation:

• dates and times given for updates are in UTC, not local time. This is to avoid making assumptions about time zone at the time of each update, and to ensure complete consistency.
• text output from commands is not tweaked or improved in any way, but is the text actually returned as Standard Output by that command. This does result in some repetition, etc., but ensures that when Apple changes the result text, LockRattler remains completely reliable.

This new version is here: lockrattler413
and in Downloads above.