I'd say to start now.
It's planned to take
years to finish, so if you wait, you won't see any of it for very long time. And when it is finished, it will take
months to play. Especially when you also need to do other things like work, as most people do. I'm not sure what I'd do if I came to it like that, maybe I wouldn't even attempt to start, because it would simply seem as too much. If you start early, it's bearable (not the best word).
Take it like "endless" TV series where you get on while it's going. Don't be discouraged by experience with other unfinished games, where you have good time with current release, and then it's constant lack of updates. It won't happen here, author is fucking graphomaniac.
And it's not just the quantity that he's good at.
I also think that keeping up with updates helps a bit against getting lost. If you get only a limited number of new events to find, it's easier then when there's too many at once.