Of what I've read is that bromate is not a problem if the dough is cooked all the way through. What can happen is what's called the 'gummy layer' just below the cheese where the bromate doesn't get cooked out.
Potassium bromate has been banned from use in food products in the EU, Canada, Nigeria, Brazil,South Korea, Peru and some other countries. It was banned in Sri Lanka in 2001 and China in 2005 and banned in my house since I found out about it.
In the United States, it has not been banned. However, the FDA has urged bakers to voluntarily stop using it. That's good enough for me to not use it.
The choice is yours but personally, I'm happier knowing I don't have bromate in my dough.