The VLAN is a software feature on the router, which is not available on the model you have.

ScreenDazed:

 

Only one LAN (wired), but two WiFi networks if that's what is meant? However, looking at it as a plumber might(!), I ran 3 cables from the ports on the HG659 to my highest use cases (4k TVs, downstairs extender) and the 4th to the switch, which I figure could get more congested as it feeds 5 other room ports (rarely used currently). A more explicit prioritisation using vlan would be a good idea with the new setup.

 

I was thinking to keep the HG659 (with WiFi off) because it offers some extra ethernet ports for my LAN, and add the mesh devices in access point mode downstream. Could a new 'lead' access point run VLANs, or would it have to be done at the 'head' of the network by the HG659 (or by a new mesh unit as gateway if I ditch the 659)?

 

I wouldn't worry about congestion on the wired network at this stage (based on your description of usage). 

What I recommend you do is: 

 

1. Keep the HG659, disable the wifi
2. Install two GWN7660E in your desired locations (or similar - gowifi has these models for $129+gst so won't break the bank)

    

    

   1. You will need a PoE switch to power these
   2. One of these will be the master device ("lead" the setup and configuration)

    

3. Now you can set up as many SSIDs (wifi network names/passwords) as you want

This doesn't give you VLAN capability, but by the sounds of it you don't need it at this point. If you decide you need it, you can upgrade your router at a later date (eventually the HG659 will give up the ghost, but could last another few years yet!)

This is pretty much exactly when we moved to a larger house which needed better wifi coverage and seamless roaming between APs. Eventually replaced the HG659 with GWN7003. Based on my experience and considering price too, I recommend the Grandstream kit.