As long as you are holding it with an internal of 140� you are fine.
It will pull fine while warm.
If you want to present it unpulled,try this.
If I were going to hold it much longer,I would just refrigerate it early.
Reheat at 250� to 140� internal and pull.
Briskets have a mind of their own,but the CS was designed for them.
Read Brisket 101 and you will get edible,at least.