ORIGINS: Americas first colonised in Central America, NOT across the Bering Strait?

Recent archaeological discoveries in Mexico and Brazil put the arrival of humans there back to 20,000 - 30,000 years ago, when the land corridor through what is now Alaska/Canada was blocked by ice https://www.nature.com/articles/d41586-020-02137-3 :

Image from https://www.nature.com/articles/d41586-020-02137-3

In a book published last year, British writer on ancient mysteries Graham Hancock theorises that the history goes back much further, by around another 100,000 years:

https://www.waterstones.com/book/america-before-the-key-to-earths-lost-civilization/graham-hancock/9781473660588

Perhaps Thor Heyerdahl was on the right track when he built Ra and Ra II to show that a papyrus boat could sail from Africa to the Americas - though why not a Polynesian type outrigger?