No, they are not. But if you're asking that because you want to build that I won't say you should not.

No, but they could be.

Mobile data plans rekt.

I am not an expert.

I’ve been thinking about how it could be interesting if clients added an opt-in “auto broadcaster” mode where the client broadcasts everything in the following feed to the other relays the user is connected to.

Would obviously be designed/recommended only for desktop/web, to prevent heavy data and battery usage on mobile.

I run a forked version of Iris that does this actually!