I told you before that this is not a good idea.
What if I was writing a ten page chapter and someone added a 4 page one in the meantime bringing changing to the timeline. That would totally mess my chapter up.
So how do we work this problem out?

You could always just write a flashback for your own character. I guess Tier and Alexander have plenty of history.
I did it myself for a couple of times. That keeps things going as well and it won't interupt our story. As a matter of fact, I'm working on one right now.