OK I know none of us would use after market antennas because it could void our warranty.
So lets just say you know a friend.

The P3S uses WiFi for bird to ground video and telemetry.
We can't change the antenna in the bird but the controller is different.
In both the bird and controller they use flat panel antennas which uses circular polarization.
Circular polarization has less multi path distortion/drop outs which is better for video.
Common aftermarket kits use panel antennas on the WiFi sides.
But you can buy vertical (stick) antennas with high gain (16-20Dbi) for cheap.
Has anyone tried these stick antannas on their controller and is the gain worth the drop outs?

I can tell you that uh,  my friend, replaced the antenna on his standard with a new pigtail and a bulkhead connector so it was possible to screw on any antenna you want.  It was also possible to screw on a patch cable to a 5.8 ghz bi-amplifier,  price around $50.00.  Having the dipole antenna provides a 360 degree coverage, no need to point at the aircraft like you do with the directional antenna kits.  And the bi-amp is 5 watts,  so the range increase is impressive.

Hi, it does increase the distance. And it would only void your friends RC, and RC normally is very reliable and don't malfunction.

"And the bi-amp is 5 watts,  so the range increase is impressive."

5 watts should give 'your friend' control beyond battery range of the bird.
But how does he handle the lack of WiFi return (video/telemetry) from the bird?
Does he have an amp on the bird too ?

roymoon Posted at 2016-9-8 07:50
"And the bi-amp is 5 watts,  so the range increase is impressive."

5 watts should give 'your friend ...

Uh,  he has not had a problem with the fpv really.  Mostly the issue was signal lost and rth,  every few seconds.  The video was actually fairly consistent.  But,  there are 2.4 ghz receiver amplifiers if such a thing were desired.

Any thing is possible

With great results in areas with lots of interference