Extending wifi

This opportunity is a bit complicated.  It illustrates why mesh WiFi systems were created in the late 2010's.

• Connecting the R7000 to the Orbi system with an Ethernet cable is nearly always the best solution.  It provides higher speed and does not interfere with any user WiFi signals.  You are SO fortunate to have an Ethernet cable that goes to that location (or can install one).
• Placing the R7000 in Access Point (AP) mode is correct.  This allows the Orbi router to 'control' the entire network in the sense of assigning network addresses to devices and ensures that the entire network is one IP subnet, so that all devices can communicate with each other.
• The "gotcha" is that this R7000 will create a WiFi network separate from the Orbi WiFi network.  Devices will not roam seamlessly between the Orbi units and the R7000.  When a mobile device moves out to the shed, it will remain connected to the house Orbi until the WiFi signal gets so terrible that the device just "gives up."  Devices may switch from a very high speed 5G WiFi connection to a lower speed 2.4G connection.  Someone carrying a phone, for example, may not notice anything different as long as they do nothing that requires high speed.  The same thing will happen in the other direction.  A device connected to the R7000 WiFi will remain connected as long as it can.
• Devices which remain in place, such as cameras, speakers, computers, thermostats, etc. etc. are blissfully unaware.  It's mobile devices that can be a problem.  You will not know until after it is working how much the "non-mesh" architecture affects you.
• The Orbi network uses an IEEE 802.11 standard which facilitates devices roaming from one Orbi unit to another (and back).  This is why they are called a "mesh" network.
• Most users would choose to set up the R7000 WiFi credentials to match the Orbi WiFi credentials because it makes everything "simpler".  Instead of, "what's the WiFi?"  Oh, where are you? (house or shed)?, it's simply, "The WiFi is...."

It is much less costly to use an existing R7000 router (free) to expand the WiFi coverage rather than invest $250 on another RBS750 satellite to place in the shed. (perhaps $100 on eBay?)