Still a dilettante at bioregional thinking, but FWIW another eco region map I’ve been staring at lately has been WWF’s: https://www.worldwildlife.org/publications/terrestrial-ecore... .
It’s intended for ESRI but can also be imported into Google Earth.
I would have thought climate change would have greatly impacted this map. Why hasn't it?
I prefer this one, from 1975 Coevolution Quarterly, by Miklos Udvardy and Theodore Oberlander:
https://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~2...