Don't know about hard pruning, but certainly cut it back in April where it's dead or looking poorly - and not before April (I'm assuming you mean Acacia dealbata)

I had one of these but in the end I reluctantly cut it down because it grew much too big much too quickly. I hope you have plenty of space! I found the same problem with sharp winds and frosts. there were no blooms that year as a result. I was told that they really dislike being pruned, but I did trim off the frosted bits after the winter was over.