Then wait for Google to adopt it at large? If it (purportedly?) exists so that Google can move multi-million line code bases from C++ to something better bit-b

Then wait for Google to adopt it at large? If it (purportedly?) exists so that Google can move multi-million line code bases from C++ to something better bit-by-bit, because it's otherwise infeasible to do so, why would Google drop it after they have ported the first million? You can simply wait to see if Chrome adopts it.