The second version should be what you're trying for. Without seeing what you're doing for sure, I couldn't tell you what you're doing wrong. It should work though.
Press start when the pokemon is created, like you said. When you get the seed, put it into the main window in rng reporter. From there generate the upcoming frames and put that frame number into the target and hit update. If it's not exactly what you were trying for, is it within 100 frames of what you were trying for? It's possible I just need a calibration for it.