As i've noticed that SE is constantly repeating it's own mistake over and over again.
It always occur that every big patching, they'll only allow players to patch right after the maintenance is over.
This causes huge server spike which some players having trouble downloading the patch over a day. Players in game too experience frequent disconnection or a number of lottery number pool error like the infamous 90k error number.
SE should be well informed that this is a huge patch and they've delayed players from experiencing the game 24hrs or more. This is just for maintenance alone. Players who had a bad connection had to bear with another few hours/day of terrible connection downloading this gigabyte chunks of update.
Being a global/international game company that's running a Premium price tag mmo service charge, se should know how to maintain it's internet traffics properly instead of letting it goes wild / astray.