> I mean generally I want fixed IPs on my local network for robustness.

What do you mean by robustness? Isn't it really stable hostnames that you want? I don't understand how fixed IPs increase resilience (to what?).

> I'm hesitant to turn it on on my local network because it does make my firewalling concerns much more critical.

Block everything coming in from outside the network. Allow established connections. That's all there is to it.

> I mean generally I want fixed IPs on my local network for robustness.

Same here, which is why I use DHCPv6. It's pretty easy to set up, nearly everything supports it, and it's super reliable.

The only catch is that Android refuses to support DHCPv6 for some reason, which is kinda annoying since it means that you need to keep SLAAC enabled if you have any Android devices on your network. Which means that your DHCPv6-supporting devices will end up with two addresses, but there aren't any real downsides to that.

> since we can just use the MAC address as an IP address

With IPv4 you need to remember ... one number per machine. The one at the end, since it's usually a /24 and everything has the same prefix.

I'm sure it's trivial to remember mac addresses from different vendors with no connection to each other too :)

> Isn't it really stable hostnames that you want?

Hostnames are another layer. Your apple tv example may advertise itself on its own. My toys don't all do that.

> I mean generally I want fixed IPs on my local network for robustness.

With IPv6 you can assign fixed unique local addresses in addition to dynamic public addresses from your ISP.

What firewalling? You don’t have an ipv4 firewall?

Honestly, it sounds more like your network is fragile rather than robust. A robust network would be able to handle the IPs changing, rather than needing them permanently set to some specific value.