My first two bags were opened by ripping along the notched precut. That left a weirdly jagged ripple that I fumbled with every time I tried to reopen the bag.
Now I use scissors to cut across the bag slightly above that line, then cut a slit in the middle of the bag. From the middle to the left, cut off the near flap. From the middle to the right, cut off the opposite flap. (Or turn the bag around and cut the same direction)
Now the two flaps are easy to grab and pull apart.
I’m currently mixing UU+Vanilla in both regular and gluten free (for my wife) so this bit of careful prep on first opening the bags has made many re-openings MUCH easier.