Each game fork has its own rules. Additional forks may be possible if the particular game would allow it at the time. Reunifications must be legal in all affected forks.
You know, I was afraid to look in here, as the last version of this game used to crash my browser when I tried to open it. And now I come in here using the powerful server at work, and I find you all standing around gossiping!
I wouldn't hold your breath, necessarily. As mentioned I did once get about 20% of the way through a move, but if I don't do it all in a very short period it usually means I have to start from scratch again.