Adding satellite #3 does not come anywhere close to breaching this recommendation.
On the forum, the general advice is to add a new satellite in a specific procedure:
Locate the new satellite near the router.
Use a web browser to open the Orbi web interface.
Select the bottom menu item, Add Orbi Satellite.
Follow the procedure shown on the web interface.
The satellite should appear on the Attached Devices screen in the top section, "Satellites" with a "Good" connection over WiFi.
Once this has happened, connect a router LAN port to one of the satellite LAN ports with an Ethernet cable.
Within a few minutes (nothing about Orbis is instant) the connection should change to "wired". Patience is a virtue. You may have to "Refresh" the Attached Devices screen several times for it to recognize the change.
Once the status has changed to "Wired - Good", then it has been established that the satellite has been linked to the router and that the satellite is capable of using the wired connection.
Then.... move the satellite to the desired location and connect it to the Ethernet cable. If the satellite fails to appear on Attached Devices (within the usual "longer than I think it should take, damn it" time), that is an indication that something is wrong with the Ethernet link.
