AFAIK most libertarians wouldn't quote The Cato Institute these days. They do still tend to agree with open borders though, believing the narrative that "good hardworking immigrant families" will be more pro-Liberty than multi-generation Americans. (and ignoring the important cultural differences with the countries those immigrants came from...)

There was a good substack posted recently that pointed out how immigrants are NOT more biased towards conservative American values, and are easily captured by the Democrats and their social programs.