NexusMods is working on their new post-vortex mod client, which does have Linux support. It can be found here on github.

This must be some weird American thing. I’ve gotten pixels on contract before in my country and I can OEM unlock and flash them no issue. If you don’t pay the cell carrier will just blacklist the IMEI. They don’t lock down the device itself.

Aegis is for Android, Ravio is an iOS app.