@PIlotbob 

I don't think that has been suggested before. I will forward that for sure.

The current devices that can do multiple SSIDs I believe are the EAP AP units, but won't work like mesh nodes along with the Deco.

@Tony Thanks.

The main reason for this request is, some smart home devices don't seem to work with the combined 2ghz/5ghz network. Maybe as new wifi 6 devices come on line, that won't be an issue. But we've had issues. 

So, I'd like to have 4 networks.

Primary (5ghz and 2ghz) - used for most devices 
Guest (5ghz and 2ghz) - password given to visitors/guests

Primary_2GHZ - for 2ghz devices only that won't worked with combined.

Primary_5GHZ - for 5ghz devices only that wor't worked with combined (not sure we've needed this though)