If you get a chance, could you test your range without amplifying the video side? Just bypass the amp with your antenna cable for video. I would like you to test my belief that amplifying only the control side will provide a range of ~2mi, which for many is adequate. My RF measurement test's show the P4 RC to have a weak control signal to the craft (less than P3P). However the video downlink from the craft to the RC seems to be really good (more than P3P). If the control signal is lost, I believe that event automatically shuts down the video link, implying the video signal is weak too, but it's not. I think a lost control signal disables the video link automatically, for some unknown reason. I believe on the P4 we only need to boost the control signal to have a good range, but I haven't had time to verify this theory.Prior to the mod I was getting only about 1800 feet due to being in a high interference are with huge power distribution towers and hills everywhere.
With the new mod my best flight was 10,384 feet.
If my theory is correct, many folks can augment the range with one amp instead of two. Along with that, the internal RC battery would last longer, powering only one amp instead of two.
If this theory holds true, it might possible to install one amp inside the RC, like Drone World claims they are doing in their Falcon P4 kit. (they are claiming two amps internal, but I don't see how that's possible)