I've read more than one cue maker saying that if you can't break with the cue they made then it isn't made right.
That being said. You might want to have a cue dedicated to breaking that you can put a hard tip on so that you don't harden up the tip on your playing cue.
And just to be clear, I've had a dedicated breaking cue for years. Sometimes I use it, sometimes I don't.
I absolutely agree with this. A well made cue can be used to break. That doesn't mean it will break as well as a dedicated break cue. It just means you won't damage your nice custom cue when you slaughter the rack in 9ball.