No, unfortunately that isn't going to help.
There are two different ways a server can be locked to new character creation. If a world is listed in the latest
world status listing under "Congested Worlds," that isn't going to change until SE reviews it and decides to re-categorize it. Things like time of day or getting in right after maintenance when fewer people are online aren't going to help in that case.
There's another way worlds can be locked. Any world will be locked to new character creation when there are lots of people online. That status changes moment by moment as people log in and log out. When
this is the only issue, then things like trying at low traffic periods or right after maintenance can usually take care of it and give you a chance to create a new character.
Unfortunately Cactuar, along with Balmung and Gilgamesh, fall into the former category. They're not going to open up until SE decides they no longer qualify as "congested".
