@TP-Link Thank you for your reply. I am aware that VLAN tagging is not required (having the Deco devices in AP mode) to isolate the Guest Wifi network from the main network. I can confirm that access of the Guest Wifi devices is limited to the gateway, but that is not my point.

I want to be able to fully separate the Guest Wifi devices by means of a VLAN, so that I can route, filter, assign DHCP IP addresses, etc. separately from the main network. I hope this explain why I would like to have the Guest Wifi network on a tagged VLAN.

How in the world can a world-wide company that makes wireless access points not understand the concept of segregating guest and home networks, using segregated VLANs to do so, and passing that information to upstream switches, routers, and firewalls? If you are speaking in an official capacity for TP-Link, then the company's position on this issue is downright astounding. Because there has been no movement on this issue, I have been seriously considering replacing the Deco M9+ units at my rental property for APs that have the capability of doing this. If TP-Link doesn't plan on addressing this need, don't expect me to advise those who seek my opinion on home networking solutions to recommend TP-Link in the future.

@TP-Link 

 

Technically Is all said why it would be very nice to have the tagging for the guest network,  to handle it by downstream equipment properly. In fact it would be nice to have both networks tagged and be able to select the tagging numbers.

Further it would be nice to remove also the SSID from guest network.

In case of the question: the user case is a normal modern household, in which you should run three separated networks: guest, household and IoT devices.