With or without the antenna no great improvement. 1302 m but zoom wheel not working. Safe working range is 1 km which is fine. I can only just about see it at that distance
How did you mount the yagis, and did they offer any noticable range increase?
To work properly these range extenders need the driven element to be in the right position relative to the director and reflector elements. The DJI RC antennas aren't standard dipole ones so probably don't lend themselves well to being made more directional with clip-on yagi style elements.
The positioning of the extenders was probably not quite what it needs to be for them to be effective. You'd kinda need them half embedded into the controller to work. The nice thing with the fold out "stick" type antennas of other DJI controllers is the sticks contain a dipole type antenna which is very similar to the active part of a yagi antenna. Clipping on the passive reflector and director elements essentially turns the stick antenna into a yagi antenna which is much more directional, and hence gives you a good "beam" to point at the drone. Here's a picture of a yagi antenna stolen of the tinterwebs for reference: