Well... they could also do other things that wouldnt make the servers to crash.

Something like an easy mode with smaller aoes (not that i want FF to get easy) or
dont let the aoe pop up at the center of the player or
(maybe not easy to include) for the players that live far away from server with higher ping they
could make the aoe on the ground visible 0,1 0,2 ... Sek bevor the castbar starts.
And iam sure there are other workarounds for SE but never mind...

Well like i said, its a first step but i hope this solution that we can experience with 2.1 will not be the last.

Keep up the good work guys