@NHBob Deco is another mesh system offered by TP-Link. To keep these two distinct take a look at this post. Any device from the URL you posted would do because that's the official OneMesh capable...

@StevieBWonder Here's your C50 guide. The range extender mode is in Chapter 6: https://static.tp-link.com/2020/202009/20200911/1910012866_Archer%20C50(EU)_UG_V1.pdf

@dme3 Sorry, I don't own C2300 to provide a config file. There's other AP scenario you can try to see if that will matter. In this case you are using the C2300 LAN port instead to connect to the main...

@dme3 Regarding DHCP flooding in AP mode you may try Kevin's suggestion from this thread and see if that helps.

@Bitterman Refer to this thread.

@MNS-Online.net You can view online device clients in the Network Map: For a short time period you can view the offline devices that have been connected In the DHCP Client list: or In the ARP list: