Charlie2, welcome to iRV2.
Sealing it as-is would be easier, and it might work. IMO, however, removing the vent is the best way to seal it. That way you can get rid of all the old, dried-up cailk and come out with a neat-looking, positive seal.
2015 DRV Tradition 375KPS
2015 Chevy Duramax 3500HD LTZ Dually
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