Company load boards and apps

I have a few load board questions.

I was wondering how many brokerages have their own load boards. So for example does CHR have their own load board?

If it is common that Brokers have their own load boards, can you get setup with them in advance? Would they have loads on there that are not on DAT?

I guess the point that I'm trying to get to is if you have however many Brokers lined up in advance that you can get email alerts from their load boards, maybe that would help all of the initial calling on a load and then having to go through filling out the broker packets on the spot as you initially start your business.

I'm certain there will be a lot of calling and filling out packets on the spot. But if you had quite a number a brokers already set up I would think that would be helpful. Is that accurate?

If that is accurate, then I would like to compile a list of them.