I found Andrew years ago (not a U.S. National but was UK who left for many years, then returned)

He’s great and his advice for the most part is sage & solid advice. Importantly, the point he speaks about people leaving the US I understand, I had similar thoughts when leaving the UK originally & met many US Founders who had left the US for the reasons he explains! The US is who loses out as those founders continue to create value for others abroad.