Alfa AC1200 WiFi in Debian

I recently built a new desktop computer, and wanted a WiFi adapter that worked well for all kinds of Linux-y things… I’m not normally able to plug the desktop in over Ethernet, so WiFi is a simple choice. After my first purchase on Amazon got delayed and screwed up, I went with the USB Alfa Network AC1200 - full model number AWUS036ACH. This is reviewed pretty well, and folks say the drivers are capable of all kinds of things.…