As a Libertarian, I’m personally pro-immigration not solely because of the benefits of idea exchange in innovation, more consumers, and the benefits in global enterprise to have a population that is more used to interacting with other cultures.
Beyond cooperation, there are also benefits to the conflict within diverse populations. Recent studies show that more culturally homogenous populations are more tolerant and less skeptical of government welfare and this lack of skepticism often leads to government growth and overreach. (refer to recent episode of EconTalk with Alberto Alessina)
I prefer society be skeptical of everything government does because you’ll have more accountability and less overreach. So in that regard diversity is key.
We see this in the LP, as the tent gets bigger we see the different factions become more skeptical than ever of everything national says and does. This is good, it holds us accountable and teaches us how to do our job with a growing and expanding libertarian coalition. Growth requires learning, diversity amplifies learning which is why I love free markets.