Unless you have a leak I think turned up flashing for a short distance should be fine. It wouldn't catch as much water. Also mortar filler you used. If it breaks, so what? As you say, it's not for water, for dust and debris. As they break, maybe you should leave it alone. The photo is small and my focus not great, but the flashing work looks very good. Is the flashing under the stucco or into a recess? Maybe could use a bead of good caulk. Caulk nowhere else.