Hi @alastair.tye.samson,
I looked at this some more and it looks like the no_log parameter will only disable the caching of events on the Volume, but not the real-time events, themselves. It also doesn’t seem to work quite right, anyway, from my testing.
Here is a alternative workaround to hopefully get you back syncing. With odrive not running (not difficult in your case), run this terminal command:
sudo launchctl unload /System/Library/LaunchDaemons/com.apple.fseventsd.plist
This will stop the fsevents daemon. Start odrive, which should start up and run normally. Make sure syncing has resumed. You should then be able to start the fsevents daemon again with this command:
sudo launchctl load /System/Library/LaunchDaemons/com.apple.fseventsd.plist
Since odrive sets up its listener at the start, it will not be tapped into fsevents and, subsequently, MacOS can’t send the malformed events for the external drive to odrive. Not ideal, but I believe it should work.