React?! Only time I react to people openly carrying is if they’re also openly being idiots. Kind of the same as how I “react” to people driving. So long as you’re behaving competently I don’t care.
Last year I was at Subway in line to order. A guy in his early 60’s was in front of me with a glock in open carry mode. No one around the restaurant was fazed by this. Police officer in line paying for his meal never batted an eye. Didn’t bother me in the least I had a S&W 642 in a Mika pocket holster in my pants pocket. Of course I live in rural Kentucky.
I generally don’t do open carry but have a couple of times when I am headed out fishing or returning and need to stop and pick something up from Walmart or a bait shop. S&W model 65 in open holster and nothing said by anyone except for maybe “is that a .357?”.