Very well done, truly! Great way to take advantage of the features Autel offers with the automatic PIV. To your point, yes, the pictures taken using PIV are basically screen shots derived directly from the video you're shooting and thus all your exposure settings carry over to the still picture which is (only) a jpg.
However, when you are not actively shooting video, and you pull the trigger on a still shot, it will jump over to the photography side of the Autel App which indeed is a completely separate setup. In that case, you will also need to decide upon and adjust your exposure settings to your liking, again, separately from the video settings. It's nice to have two separate menus and settings for each of the two camera setups, but it does require some preplanning.
With respect to their RAW (DNG) images, no doubt they require some extra effort and attention, but many serious photographers find it more than worth it. I am hardly a pro photographer, but do enjoy pushing the envelope and I've had very good results shooting DNG files. Raw images retain much more data and thus are higher quality images with greater color space and bit depth which gives you more latitude to adjust them in post processing before introducing artifacts and corrupting the image.
Adobe Lightroom is fantastic in handling DNG files. When looking at a DNG file in a standard viewer, such as Faststone, it looks awful. But Lightroom applies corrections to the image the moment you drop it into the software including lens correction, which apparently the DNG files coming out of this drone have a built in profile which Lightroom reads and applies.
Again, I'm not a pro, there are people on this forum WAY more advanced in their understanding of imagery, and it's entirely possible someone will follow this up and either correct me, or add to my thoughts. Either way you slice it, you're shots are looking great and most importantly, it appears you're having fun and that's always the bottom line. Bravo!