Balancing By Adjusting the Flame Control.
The BS has a very simple tool free way to adjust overall top to bottom heat, especially if you are only making a pie or a two at a time, by adjusting preheat times and the flame control on the front of the BS. Say you find that the bottom is burning before the top browns. One option is to use a shorter preheat time and set the flame at the front to a medium low. When you launch the pie, you then turn the flame up to full. The air in the chamber will increase its temp much quicker than the lower stone, which has greater mass, and so the top should brown quicker while the bottom should now take longer to brown. Of course, this will not work if you are baking multiple pies unless you turn down the flame, and give enough time to allow the lower stone to cool down. That is why many of the other mods are used.
While it might be possible to do this without an IR gun, I don't think so. Before you do any mods, get an IR Gun and keep track of the lower stone temp at launch and how that impacts your pie. Some like to launch around 600, others like 700 or even higher. Again, the type of pie, flour, cheese, topping, and desire for char all impact what will be best for you. You don't need an expensive IR gun, and you don't need to point it at any particular part of the stone, as long as you always point it at the same place each time, you should get some fairly quick feedback at good launch temps for your pie.
One other technique to increase top browning is called doming. When the bottom is done, you use the peel to lift the pie off the lower stone, and hold it a little closer to the upper stone for a few seconds. I say a few seconds, because I only tried this technique once, and maybe I held it to close to the upper stone, it seemed like only 10 seconds or so, but when I took the pie out, I had a lot of charcoal colored cheese - which doesn't look good, and surprisingly enough, does not taste very well either. When used carefully, doming can help you accelerate top browning, just be very cautious the first few times you try it.
Another option, which I have done when I let the bottom stone heat up too much , and didn't have the patience to let it cool down is to use a pizza screen Amazon 15 inch screen, or pizza pan. You launch the pie directly on the stone, and come back a minute or so later, if the pie is nearly done, you take it out, put it on a pizza screen, or pizza pie, and put it back in the BS. Since the bottom is not resting on the stone, it won't brown as quickly as it did when it was sitting on the stone, and you can then let the top brown a little more.