Other than checking the log for wake events is there a way to check discoveryd was disabled and re-enabled?
Well, you obviously can't check if discoveryd is unloaded during sleep directly, but you can check that it is loaded (the sudo is very important here so make sure to remember it):
sudo launchctl list | grep com.apple.networking.discoveryd
This should return something. Otherwise discoveryd is not loaded.
Another thing you can try before adding /Library/LaunchDaemons/de.bernhard-baehr.sleepwatcher.plist is to check and see if your rc scripts work. I.e
/usr/local/sbin/sleepwatcher -V -s /etc/rc.sleep in a terminal and then try to sleep or
/usr/local/sbin/sleepwatcher -V -s /etc/rc.sleep -w /etc/rc.wakeup and then try to sleep
In both these cases the terminal window will not report anything until you actually wake up from sleep again, and you have to initiate sleep manually (or wait until automatic sleep). Enter CTRL+C to stop SleepWatcher after testing.
Refer to the SleepWatcher documentation for more details.