Boyfriends kids are being moved out of state

To make a veryyyy long story short, my boyfriend has 2 children from a previous relationship. The mom of these children is borderline psychotic on most days and I hate to sound judgmental but the way she treats my boyfriend as a person/father of her children is absolutely terrible and pathetic. Anyway, he hasn’t seen his kids in months because she won’t let him, and he’s been trying to save up the money to get a lawyer and take her to court. Well, today he got a phone call that she is moving the kids 8 hours away to another state NEXT WEEK. He went and filed custody papers as soon as he found out but doesn’t know if she’ll get served before she moves. Has anyone ever been through this and have any advice?

Attaching messages just to let you all know what kind of person we’re dealing with here. Even told him in the messages she “doesn’t have time” to let him see his children before she moves them 8 hours away.

EDIT: A lot of you are seeing this way different than it is. I should’ve added that my boyfriend and I have done a lot for these kids when she didn’t step up or “didn’t feel like it”. She doesn’t have a car to get his oldest to school so she had to pull her out, doesn’t have a job and relies off the government. Which doesn’t have anything to do with it but sheds a little more light. We used to have them almost every day until she decided to use them as a pawn.