Baking a pizza in this manner is pretty much like going to war.
LOL. The pies are looking great, but I can see how this configuration might be stressing you out.
I don't have a fire alarm in the kitchen, but I've set off countless alarms at friend's homes.
It's not going to solve your alarm issue, but, if you wanted to see if you could take this configuration further, you could try some kind of probe insulating condom. That way, you should be able to use the entire broiler at higher temps.
The blackstone is a great oven, but I'm not sure if they ship to Australia, and, if they do, it's going to be costly.