Yes they are in the feet but they face fwd of craft since the Tello was intended to be a "selfie" cam in more instances than others. I am in no way saying your idea won't work, just trying to reinforce already established theories on how wifi radio signals work.
Here is an example of what I'm trying to say, I did an experiment with my new phone a year ago then, I wondered how much great signal I could get during a speed test to my router, using the same "host server" I used Chrome's speed test easily searched in address bar. From my room it was descent. (One bedroom apartment) then I did 10 feet away, Mbps was increasing, then I did 5 feet, wow was I amazed how much better this new phone did compared to my old phone, then I did the test with the back of my phone up against the routers side, it's a upright internal antenna based router. Anyways my signal went way down, tried several times, not much better. Back up a couple feet and it's super fast again.
Wifi antennas have a negative zone, those that use 180 degree patch style antennas like mine. I know because I took mine apart at one point. Like a bubble.
mounted on top and powered from the TELLO battery charger slot.
