Guest WiFi on two Routers

How do you configure a guest WiFi network when using two OpenWRT routers?
I have followed to configure a guest network on one router. I then was able to install and configure OpenNDS so that my guests can login and have internet and keep my home network isolated and not share my home network WiFi Key.

I already have 802.11r/k/v enabled for my home network, it would be nice to have the same thing working in my guest network so that if a guest is logged into they can roam to the next Wireless Access Point if needed.

What I'm guessing I need to do is somehow bridge the guest networks between the routers so that DHCP server and OpenNDS is forwarded from my 2nd router to my first router.

Has anyone done something like this?
What is the best way / recommended way to have an isolated guest network that can roam between two access points?

Thanks in advance

Isolate with vlans all the way up to the router.
Assign the guest to an unmanaged interface. Use the lan interface for management.
More or less like a dumbAP but with vlans.

Thanks trendy, I was wondering about isolating the guest network on its own VLAN. I forgot to remove the management part, thanks for reminding me of that.

Can I have the two guest VLANs connected together between the two OpenWRT routers and have the one router interface be the DHCP server for both? I guess the router that is the DHCP server needs to be the one to provide the internet access.

I have a single GigE cable going from each router to a switch, this will be providing my home network / internet as well as the guest VLAN would that be a problem?

Are there any tutorials that explain how I can do this?

If you want to have proper roaming between the access points, then there must be one guest vlan enabled on all access points and backhauling to the router.

No, that is the point of vlans.

I am not sure, for what you want to do exactly. There is for creating vlans, so you know how to create one and make a trunk port for the uplink.
Follow the first 2 steps of dumbAP with guest but use unmanaged protocol instead of static for the guest interface. Assign the guest interface on the guest vlan subinterface. That should do it.