I forget that you;re not giggin with a band and looking to throw rated power at them.
I think the fact they show usable response to 800 indicates you can operate them that low, you just have to be sure to de-rate the power spec accordingly.
The danger is over-excursion, and at 800 i think you have plenty of safety margin before you have to worry about that.
And we should also probably consider that since the data is in the form of a catalog page, it may be massaged a bit to help persuade a potential buyer to the next offering "up" the ladder.