I agree. We started visiting maybe sophomore year and like you they were sort of opportunistic tours. The first set was in the Boston area because we were in town for the marathon. We did some in Chicago when we were visiting family one year too. We tried not to overdo it or make it super stressful but I think the tours helped my D start to get an idea of what she was looking for. My D missed a lot of school due to her major activity which was a sport not affiliated with her school, so taking any more time off to tour was hard so we took advantage of times we were already traveling. My D was the type of kid who wanted to SEE schools before applying so we did a lot of tours. Funny enough the school she ended up at was the one school we didn’t visit before she applied and had to quick rush there after she was admitted.
I would say those early tours were different than the later ones when she had started to pinpoint a major and understood more what she wanted. But they were still helpful.