Maybe you are a glutton for punishment and want to figure out how to use your Windows Generated Self Signed Cert with webpack for building an extension against localhost. While poorly documented, it isn’t that hard.
In Powershell, follow the top Example but set your DNS name to localhost (or wherever you are pointing your dev extension at).
(Double click the .pfx file to install it to your Cert Storage if you have other uses for it in the Windows world)
Then copy the .pfx file to wherever you have the conf directory for your webpack server.
Then add the following to your webpack-dev-server start command
--https --pfx=./test_cert.pfx --pfx-passphrase=sample
Hope this someday saves someone a 1/2 hour of looking into that nightmare!