Yep, its always "you need to read this to understand", or here is a statistic that proves my point.

> I think in-person can be good for very high level arguments,

Its good for exploration. But there needs to be trust between the parties in that no-one is trying to one-up the other or win some argument - this makes people defensive. Also arguing in front of others can cause this defensive effect as well.

> My grandmother (RIP) said in her youth (1930s), they didn't know how their neighbor voted, how their teachers voted, and they might not even know how their spouse voted. I like that.

100%. You want to maximize as many opportunities for people to get along with each other as much as possible despite their differences. People's views will change and evolve over time and very rarely from intimidation or pressure.