Can an ORBI be setup as an AP while mainting mesh functionality?

I would like to help a neighbor out with out of the oridnary (for me) WiFi setup. He has two homes on his property and would like to bring internet connectivity to second property. The primary residence has a T-Mobile 5g home internet wifi router. From my understanding, there are is not much in the way of advanced configuration available no that device, but it does have a few lan ports.

We plan to run ~150 feet of ethernet from the T-Mobile unit out to the second buiding and install a two pack Orbi system in the second building. Since I am likely unable to bridge the T-Mobile unit, I am considering setting up the Orbi system as an AP and letting the T-Mo unit handle routing. I would also like to name the SSID something different than what the T-Mo is using and try to adjust channels to avoid overlap. 

My questions: If I put an Orbi in to AP mode, can it still mesh the second satellite unit that came with the Orbi? I have never messed with a mesh system in AP mode and donj't know what to expect.  Does my logic make sense of giving the Orbi network a separate SSID from the main unit and makign sure there is no channel over lap?