It also behaves differently when Singles go offline; 2.3.6 just exited (which was good) but 2.4.1 and 2.4.2 just mark them as 'OFF' and do not exit (bad).
This was requested, and seemed logical. Would it be more acceptable to you, if it automatically reenabled the devices when they're plugged back in?
Luke, one benefit of exiting is that cgminer can then be executed in a 'forever loop' script such as this, which is useful for automated and unattended error recovery (in lieu of something like akbash):
:loop
cgminer
waitfor xx seconds
goto loop
Because cgminer is re-run automatically by the script, it re-enables all the Singles. This was the behavior with 2.3.6, and worked well.
With 2.4.1 and 2.4.2, if any Singles goes offline for whatever reason (temporary power failure, USB cable unplugged, it crashes, ...) cgminer marks it as OFF and it can never be re-enabled unless you quit cgminer and re-run it. This makes it less suitable for this type of automated error recovery.
Now, if cgminer could be altered to re-enable any devices when they are plugged back in, that would be a significant improvement.