How to add vlan with mesh11sd

OpenWRT 24.10.1 on 3 x OpenWRT One nodes

uci set mesh11sd.setup.portal_detect='1' # auto
did not work with my PPPoE wan connection, so I've set it to '1' for the portal and '5' for the peers.

I've got mesh11sd working with my PPPoE wan connection and now I want to make some changes without going back to scratch and re-flashing.

Since flashing I've made some changes using uci (only on the portal) which seem to work fine:

  1. set DNS servers in network.wan/wan6
  2. set firewall redirect for external access to Home Assistant
  3. set dhcp hosts for static leases (fixed IP addresses)

I guess all this only happens on the portal node, so it's reasonable that it works like this.

I want to try:

service mesh11sd stop
uci set mesh11sd.setup.auto_mesh_band='5g'
uci commit mesh11sd
service mesh11sd start

to see if its reliable and faster than '2g40'. Should this work if I do it on all nodes?

Likewise I want to try configuring the Guest vlan (vtun_* settings). Should this work if I do it on all nodes?

Lastly I want to configure another second vlan for IOT. Because I'm using Home Assistant locally, my IOT is predominantly local and devices on this vlan will have no or highly restricted internet access, but the Home Assistant instance will need access to them all. So it's quite different to the Guest network. How can I do this?