So what's the question? You answered it yourself. And actually there IS NO hardware concept to have a modem with firmware that's not modifiable, the chip manufacturers won't use fuse ROM to store their firmware, and as soon as it's flash it CAN get modified. And you can't make sure that what you "read out from ROM" is the actual content and not some fake that the malware delivers to you. Regarding FSF approval: we are not interested in getting THAT approval, we take pride in our own concept being better than what FSF defines. The idea of immutable firmware is based on a flawed concept, it doesn't help for anything.