We had someone call us and ask about the lead flashing that was on top of the shingles on the downside of the vent. They were concerned as all our pictures don’t show this.
Its actually the way different roofers use the lead. In Florida we bury the foot under the shingles, but in Texas its common to leave it exposed, the theory being it provides a better seal. Its not very attractive however.
Regardless, both ways are fine to seal a vent, and neither interfere with how a Critter Quitter works.