Attempted to RNG Suicune. My frame was 501. Hit 503 a few times and 493 pretty often. Eventually got it after around 50 mins. I screwed up advancing the frame though. :( And the frame was 495... took me over an hour and a half.
I think the problem might be somewhere else though... I was using Method J... should it be K? And can Synchronizers be KOed as long as they're in the first slot?
You should definitely be using method K. To help you keep track of frames make sure you use the RNGreporters function from the main screen. Click Method K and if you are using a Synchronzier click that. Then input your seed and click the generate button. That way you can just use the arrows to move from frame to frame as you call Elm. This has helped me to keep track for a while and I am sure will help you.
Also, it doesn't matter if your Synchronizer is KO'ed or not.