Armored Core 4 screen flicker with ATS

That's normal, that's why it's a setting and not something enabled by default, as it can cause issues.

It's not mentioned in the wiki because it's not a default setting, otherwise it would be flooded with a list of settings you can enable to break the game, as you can break it with many more settings.

You can still open a ticket on GitHub though to track it, to see if something can be done about it.