integrating AREDN into an existing network..

Yes, the instructions still apply.     However, the .pdf diagram is not possible (and different than the setup as described in the instructions).   

These instructions munge the LAN network of the mesh node in with a home network with shared address space.   When communicating to other devices on the mesh network, the 192.168.1.x client goes though a NAT through the local mesh node.   Everyone else on the mesh thinks the client is the 10.x.x.x address of the mesh node, and has a mechanism to route back.

The relationship of this 192.168.1.x network to the mesh 10.x.x.x network is the essentially the same as the relationship to the internet.   Mesh and Internet devices can not directly reach in, however port forwards can be setup (from internet and the mesh) to access services on the 192.18.1.x network.   The 192.168.1.x clients can reach out to addresses on both the mesh and the internet, and most things work.  Some applications, e.g. voip phones, may not work with out more complex port forwarding rules to figure out.

Joe AE6XE
 

1. Remove the two AREDN nodes.
2. Replace them with two radios with standard Ubiquiti firmware running as transparent bridge between the zones.
3. Add managed switches at the edges of the wireless shot, with Trunk ports crossing the wireless shot.
4. Configure untagged access ports for your regular network end devices.
5. Configure tagged access ports for VLAN 2, for DtD, and connect your AREDN nodes to these ports.
6. Connect end devices to both networks (standard untagged network on the switches and the AREDN LAN(s) at each node) using two network interfaces, LAN plus Wireless, or two LANs.

This is just my personal preference, I like the idea of trunking the point to point links, as Part 15 operation. This allows me to not only run AREDN across two locations, but also any other VLANs I may need to extend in the future.