Question about TP-Link Deco X60 (3-pack)

Yes, it is possible. When connected via the LAN cable, the devices will no longer perform a mesh function via WLAN, as the LAN connection is used as a backhaul.

A very inexpensive WiFi 6 solution would be, for example, the Xiaomi AX3000 Mesh System. Two kits with a total of even 4 routers cost about 250 Swiss francs and have four Gbit Ethernet connections per mesh router (3 x LAN and 1 x WAN). Up to 10 routers can be used in the Xiaomi mesh system.

As already mentioned, the setup of the Decos with Ethernet backhaul is somewhat complex, because it is possible to create a network loop where nothing works properly.

Be sure to read the instructions here:

https://www.tp-link.com/us...

I have connected the main unit on the ground floor with RJ45 to the router (UPC). WLAN is switched off on this unit. The second device is on the first floor, the third on the second floor. After the installation (went without problems) I have a gapless WLAN down to the basement (concrete ceiling) and to the seating area in the garden (approx. 20 metres away from the first device, brick wall). At each station, you can connect 2 clients without WLAN via RJ45. Previously I had an impossible mixture of Powerlan and a pair of repeaters. I am very satisfied!

Yes, that is possible. But it has to be "strangled" a bit during the first setup because it is not intended by the setup wizard. It is essential to observe the sequence: First device directly to the router or to the patch panel in the basement via RJ45. Second device must be connected DIRECTLY via RJ45 to the first device (it has two connections). Third device must be connected DIRECTLY to the second. So ALL in series and in no case parallel to the router, otherwise the repeater mode cannot be set up via cable and the devices automatically set up a WLan among themselves. It took me over an hour to figure this out(!).
Otherwise I am satisfied with the devices.

Each unit has an RJ45 socket at the back.