Do you think people should be adding it to flour as an ingriduent themselves?
Honestly, up until Philip posted that link, I didn't know it was available on a retail level.
It's probably not very cost effective, you'd need a very precise scale for measurement (~.015g per Kg flour), and you'd need to be careful, but, sure, if someone is conscientious about it, why not? It would be considerably safer than working with lye for pretzels or bagels, and many people seem to do that without any issues.
A little more research is necessary- such as how long bromate requires to oxidize flour and what kind of shelf life it has, but, for, say, someone in California, this could be a more viable route than paying exorbitant shipping charges.