Hello guys. Could you please take a look at this. You don't need to look at the whole thing, and it certainly won't be exciting anyway, as I accidentally left the camera pointing straight downwards the whole time (bright evening light made it hard for me to see the screen).

I'm getting what I perceive to be a strong frame shudder effect in the segment from 2:00 to 2:20 appx. Frame rate: shutter speed was 25:50 (I think I've stated that the right way round).

If this isn't jello, then what is it, and how can I correct it? If it is jello, how can I change my settings?

Mind you come to think of it, I was using the transmitter's "exposure" dial on the fly, as you can see in the video...which I guess might have changed those settings to anything.

I don't see jello.  There are some quick moves where the camera can't keep up but it is minimal.  These aren't cinema quality cameras here.  They may record on 4k but you wont see Hollywood using exclusively.  I'd get more time under your belt and make sure they are slow movements.  Looks better anyway.  I'm not saying my videos are the greatest. Just my two cents.   

How many times did you bounce after that landing?  Just kidding, I think the camera angle pointed straight down makes it look much worse.

I dont think jello in your video, looks like normal to me

No jello in that video that I could see.. Maybe try again with it facing forwards and on auto.

No Jello.  As was stated a downward pointed camera has cinematic use but over water with no defining features does nothing for the viewer.  Glad you are enjoying your P3.