Thank you @aibd for linking to @prflsjn’s very informative post, and thank you @prflsjn for providing so much detailed information! That was the fix for me.
When the phone got to fastbootd mode I did need the driver MathiasV linked to, and Window finally allowed me to install it.
The bold commands below failed for me… how important are those for the future of this phone? It started fine so hopefully not important.