The 5e Inquisitive Subclass allows perception checks as a bonus action. Would that matter in a heavily obscured area during combat?

Let’s say an Inquisitive is in a fog cloud. By my understanding, advantage and disadvantage cancels out if you are fighting someone else in that cloud. But if you were able to make a bonus perception check (and succeed) before attacking, could that negate your disadvantage?

As far as I can tell, there are no direct rule applications but I just wondered if someone had any thoughts on it. I guess in my head, using your action to search for someone when you can’t see due to environmental conditions them isn’t that useful for attacking purposes. But if you were to use a bonus action (in effect searching and attacking near simultaneously) would that change anything?

Same question for attacking from outside said hazard. I search, find, and shoot arrow – negate disadvantage?