Frame dropping is something you can not 100% avoid. Using a wifi repeater is good and helps a lot to keep this Problem small. But until the
tello has no SD-Card (and can save the file directly without the smartphone) frame dropping will be every time an issue.
The
tello is a nice litte drone. The photos are better than the videos and if video is really the main reason to fly maybe another video drone would be better (Spark or MavicAIr,...).
For me Video is the main reason and i try it with the
tello. There are a lot of possibilities. But you have to know the weak points of the drone.