For Industry 4.0, yes telemetry is important. But, not all industrial cares about telemetry. In that case, what I have seen, is that all the data is sent to a c

For Industry 4.0, yes telemetry is important. But, not all industrial cares about telemetry. In that case, what I have seen, is that all the data is sent to a concentrator that has the network stack. This is often a "high-end" (perhaps Linux based) machine with network access. Is not that every chip in a system is connected to the network. For what Rust matters, I'm really want to see high-level stack written on it, or libraries like libssl. I think that's where Rust should be placed not going any lower (in levels/layers). Regarding ARM, it depends. It's not just a matter of bits over price. Pretty often the combination of features you want are not available in an ARM chip. For example, long term support, some specialized tool, temperature/power supply range, price, available peripherals, etc. And sometimes you might be required to work on some strange 32-bit CISC from Renesas just because the salesperson took the purchasing manager to dinner somewhere. And yes, everything is hackable no matter the language you use. If you open the case and cut some PCB traces you might read and inject some data making some device to misbehave. But that's the way it is and I don't see the world falling apart because of this. If it really matters, then (electronically) tamper-proof your case would be my advice. Again, is my honest opinion and the opinion of many embedded developers I work and know: vulnerability FUD is just noise. I'm just being sincere. Of course if you make locks you have to make your system secure. The other billion of embedded applications might not. And that's it.