Of course Japan will have regulations on flashing images, thanks to that infamous Pokemon incident.
Mind you I saw the Poltergeist film on Sky Cinema the other night and the amount of flashing images in that particularly around the static on the TV in the film was probably just on the borderline of acceptable IMO.
It's very simple. It passes or it fails. Often things that pass easily look like they should fail, and stuff you wouldn't necessarily consider to be problematic will fail badly (the spatial pattern tests can cause US flags in graphics to cause a fail for instance)
Theere are a number of different testing devices that are approved - and they don't all behave identically though...
That being said, a lot of visual effects seem to apply in video and cinema films that it's questionable sometimes whether if it was a TV show they'd get away with it, unless there's a higher threshold for a cinematic film when its aired on TV?
The rules for all TV content are the same - they aren't different for different sources or genres. I don't know if there are any regulations for cinema - but the wider field of view (which could make things worse) and the generally dimmer (which could make things better) light levels could change the parameters.