following for when my Prem finally arrives

Instead of looking for a USB adapter, as compatibility will be limited to what drivers Stern has included in their software, you're probably better off looking for a 5GHz WiFi to Ethernet adapter. Something like this could do the trick: https://www.brostrend.com/products/e1 That way you can use the wired Ethernet port on the mainboard and not need to worry about any drivers. So long as Stern supports a wired connection you should be able to use an Ethernet to WiFi adapter. For that particular model you'll need to figure out how you'll tap off the service power plug to power it. There are adapters that can power from a USB port (ex., those by VONETS) but I didn't see any 5GHz ones. I've used similar adapters for things like the original Xbox and Golden Tee arcade cabinets in order to get them from Ethernet to WiFi.

And personal preference (plus that of the local pinball arcade) is to do updates via USB thumb drive anyway. More "front end" work but probably more likely to be without problems.

Just bought a second hand iron maiden premium, it doesn't come with the WiFi, am also interested in a solution