Is the amount of shaking spots in DPPt with every seed the same? Or does it vary? Maybe I can use that to determine my delay.
According to the on-site Pokeradar RNG guide:
"To maximize the number of patches, stand in the middle of a large grass patch as shown above to always get 4 radar patches. Once you've determined the location of your patches, make a note of them, as the radar patch locations will be in the exact same locations as long as you've hit your seed, and as long as you haven't saved."
So the number of patches should be always 4, but their locations do correspond to a given seed (and will not change if you don't save and start over). So you can use their locations to determine your delay (or, at least, whether you hit your target seed or not)