Hello,
It looks like this change might have introduced a gap into a couple of townlands - see https://www.openstreetmap.org/relation/4204334#map=19/54.816293/-6.130655 and https://www.openstreetmap.org/relation/4161726#map=19/54.816293/-6.130655 .  Are you able to fill it in or would you like help with that?
Best Regards,
Andy
