DavidR, very interesting.
So... is this just the old "Windows Firewall" with a new name? Nothing changed?
As far as I'm aware that is all it is, just MS rebranding everything with Defender in the name.
When I first used my new win10 laptop a little over a year ago, it was just plain old Windows Firewall.
These changes may have come in the Creators/Fall Creators Update as I haven't used any other firewall on this win10 laptop.