Yo, about the latest update to your info dump post in the frlg research thread --- the game accepts input during the time of the frame, not just on that specific frame itself. I know this because of the odd method testing I did (skipping the intro and all); if you could only input exactly on the frame, my results wouldn't have been possible.
So yeah, I'm pretty certain that you can hit A any time and it'll register for seed generation, at least without an emulator. For those advancing the frame with a VBA, however, those 60/256 frame restrictions would apply.