Would this topology work?

[AKLT]

The reason for this layout is due to the fact some smart home devices can only use 2.4GHz and I'd like to keep band steering available on the main Wifi, hence having a separate IoT network.

And I'd like to keep guests off both networks and on their own separate one.

Since the FWG has 3 other ports, I wanted to use the last one for my NAS. Or should I have my NAS on the same LAN port as the main Main Wifi?

Port 1: Main Wifi
Port 2: Split via Switch - IoT Wifi + Guest Wifi (2 different APs, SSIDs)
Port 3: NAS
Port 4: WAN

The ports are 1gig ports if that matters
Sorry if its confusing, glad to clarify if required.

 

[ColinTaylor]

If I'm understanding your diagram correctly the most obvious potential problem is network loop created from the FWG port 1 to port 2, via two switches and two access points.

It's also not clear how you're segregating your IoT and guest networks from your main network. I'm assuming you're doing it with VLANs, but I'm not sure how if all your switches are unmanaged.

 

[AKLT]

If I'm understanding your diagram correctly the most obvious potential problem is network loop created from the FWG port 1 to port 2, via two switches and two access points.

It's also not clear how you're segregating your IoT and guest networks from your main network. I'm assuming you're doing it with VLANs, but I'm not sure how if all your switches are unmanaged.

I see what you mean this won't work then. Thanks a lot for highlighting it.
Yea I'm not particularly savvy in networking so I probably will screw up using a managed switch haha.

 

[Tech9]

Wireless AP, Wireless AP (IoT) and Wireless AP (Guest) can be on the same AP, VLAN separated SSIDs, depending on the hardware you use.