Update: I understood how non programmed start ballast in the US and Canada, can flash like EOLEDs during brownout, despite CFL and cheap electronic ballasts don't does this in Israel, and instead simply dimming to partial discharge or turning off:
As the mains voltage in North America is 120V, it is enough that the voltage would drop to 95-105V for 120V CFLs, and non programmed start ballasts to flash at full output. This voltage range is too narrow to dim the lamps.
At 220-240V countries, the range of lowering the mains voltage during a brownout is very wide, and the CFLs and cheap electronic ballasts dimming as the mains voltage lowering, until the voltage reaches 95-105V and the lamps extinguish to partial discharge or shut off.
This is the conclusion I reached.

I've seen flashing happen in a building where the mains voltage to lights was 277v (how low that voltage actually dropped, I don't know...but on the 120v supply it got down to around 60v, so I'm assuming 277v was also around half normal  - 138v)
...one phase was on full, one was half-voltage, one was out completely.

Yup.  Dropped phase somewhere.  Happens at some of my church buildings from time to time and when it does and the lights were left on, there is usually a good number of tubes I'm replacing soon, especially on the newer philips lamps, which have the cathodes that let go.