Raw video from a Phantom? I wish
My friend, this is compressed to H264/65, only high end video cams records raw internally.
On the other hand, the codec Dji uses is a pia to use, its even harder to run than a raw prores file with 4 times higher bitrates.
Do as suggested, convert to prores and then start to work with your files, it will be butter smooth, even if the files gets ten times larger.
The way i see it, its no other alternatives from these heavy 4k files coming off this camera.
I got a dedicated video rendering machine myself, even that struggles with these files coming straight off the card.