tri-band and dual band in AiMesh

[jaxfoojx]

Hello all, so I am now having a AC86U as my main router and wanted to upgrade it to AX for Wi-Fi 6 and I am leaning towards a tri-band AX model since I now can build a AiMesh with 2 Asus router and from Asus FAQ, it mention I still can do a DWB -> https://www.asus.com/us/support/FAQ/1039646/
On the very page, it mentioned If you have already set up 3 different WiFi names for each band, the dedicated backhaul will not automatically establish. In order to do so, you'll need to enable Smart Connect.
Does anyone knows, if I do not use Smart Connect, is there any way I could configure for my AC86U node to connect to the third band of the AX router for backhaul?

Some answers that some of yall might have. Yup, I can only use wireless backhaul, routing wire need someone's approval, which may come at the price of a luxury bag.

 

[OzarkEdge]

Do you have any existing coax cable you can use for a wired backhaul?

OE

 

[jaxfoojx]

Do you have any existing coax cable you can use for a wired backhaul?

OE

Nope. The only "cabling" I can do is powerline, but I heard the connection stability is purely based on how the electrical wire are being ran in the house