Okay, so I factory reset the thing, and to use the headset at all, the setup requires that you have to log in with at least a Meta account (only an email address needed, no Facebook), and you have to pair it with an app on your phone that controls things like developer mode. There’s no way around it, the first thing you are greeted with in the headset is a pairing code for the app, and you need the app to make the headset work afaict. I didn’t investigate if there’s a desktop app or web app.
Side note, apparently developer mode now requires a phone number or credit card attached to the account. Maybe a vanilla visa could work, not sure. I’ve already bought stuff through the quest store, so enabling developer mode was just a click for me. I used developer mode to install sidequest just now to see what it’s about, but neither it nor developer mode are needed for Steam link.
Mayyybe you could make a Meta account with an email address made just for the headset, maybe run the Android app in an emulator, but that would be a bit of a hassle imo. I suppose you could isolate the headset into a subnet, or it’s own SSID if you’ve got the gear for that, and keep it quarantined most of the time and just let it reach out here and there for updates, but who knows if it blurts out any collected telemetry while it gets the update. You may not have to let it out for updates at all however; when I booted into factory reset there was a “sideload updates” option, so maybe you could update it manually offline.
Honestly, as good as this headset is for the price, if I were concerned with absolute privacy, I would just cough up the dough for a competitors OLED unit. I could spend all of the hours I was frigging around with the headset doing OT at work instead, and just use that money to get something better without the pain and hassle. I get that’s not an option for everyone though.
Perhaps as an affordable compromise, if you don’t mind temporarily leaking a little data to Meta one time, you could do the normal setup but with an email just for the unit, install the app for 5 minutes on an old phone or tablet without a SIM for the setup, get Steam link on the headset, uninstall the app on the phone, and drop the headset into whatever Wi-Fi isolation you can conjure up. Maybe an isolated SSID or even easier, an affordable 5g router dedicated just to VR.
I don’t trust Meta either, but I gotta admit, it actually feels kinda neat to experience their $30 billion dollar metaverse disaster first hand while it’s still around to look at. For the record, the only protection I did was make a Meta account. I don’t use Facebook.