My RM500 is workable, but the product has a nasty compass issue that can cause you to chase your tail. Well known, and DJI refuses to admit the problem nor do anything to fix it. A nag point for me.
The Micro SD card must be true U3, V30 rated, and it helps to be
A2 as well. Anything less and you'll end up with capture issues at 4k/60. My Samsung Pro Plus cards do 160R/120W on my PC. My Samsung EVO Select cards I started with only did 90R/80W and had odd problems in both the controller and the drone, so I bought the better cards and quite happy I did.
I do not cache video at the controller. If I want to record the flight locally, I turn on the RM500 video recorder; that captures the entire screen and everything that is happening. I only save video on the drone and use the SMOOTH (720p) downlink option for the screen. The most important thing to capture locally is what the DJI Fly app is doing and telling you. Lets you go back and closely review the battery status, warning, etc.
To move video from the RM500, plug in a USB stick, use file manager to copy the files. Swapping the SD card in and out is painful and I've lost information. The SD card MUST be "ejected" or the files are all lost (0 byte). So just plug in a USB stick.
Again - personal choice, but local caching is just another function that slows down the already loaded up controller. Just do screen record. Pull down the menu from the top of the screen, select RECORD.
