I suppose it depends how regular the signal is otherwise. If a dip happens super-regularly (which I guess it would with single star planet orbits), it might be

I suppose it depends how regular the signal is otherwise. If a dip happens super-regularly (which I guess it would with single star planet orbits), it might be small relative to pointwise noise of the detector, but large enough to be detected over time (if you have the observations). Your point on period length stands. And anyway I'm just waxing lyrical, I'm a statistician and amateur stargazer not a pro :)