I do have one, but I don't remember any pitfalls while configuring: turn on
tello and repeater, connect the phone to repeater network, use browser to visit tplinkrepeater.net, choose
tello network on the page -- that's it, other settings are optional. Just make it fast enough, so
tello wouldn't get hot enough to shutdown (I have used a fan to cool it, maybe just turning on motors without takeoff will do? After all,
tello has four fans builtin
)