Doug Casey lives in Argentina and talked briefly about Milei in his recent talk with Saifedean. The tldr is he likes him but isn't involved in his campaign. I highly recommend the episode:

The Bitcoin Standard Podcast: 180. Applied Anarcho-Capitalism with Doug Casey

Episode webpage: https://saifedean.com/podcast/

Media file: https://www.buzzsprout.com/1849151/13368003-180-applied-anarcho-capitalism-with-doug-casey.mp3