So just a question on your set up, does this mean you now have one SSID across the entire house? and i see you have used Ethernet between the two devices, so is this really just working as an access point rather than a wireless mesh?
i would still call it mesh rather than a second AP, given it still does the core "Mesh" wireless.
so instead of broadcasting different channels and your devices switching, the AP and Mesh will broadcast the same channel.
while not the best result for "total throughput" for 99.9999% of users, it gives a better experience than actually roaming channels