Bryan,
There are several ways to increase crust flavors naturally (that is, without using special chemical additives), but they usually entail using natural starters/preferments or long fermentation times, either at room temperature or in the refrigerator (usually several days). For doughs that are to be made and used in the same day, a preferment such as you used, or maybe in another form such as a sponge or biga, is one of the few ways to achieve better crust flavors naturally. A simple change, such as going to a higher-protein flour, such as a high-gluten flour, will itself give you more crust flavor because of the increased protein content. Using honey, non-diastatic barley malt syrup, a bit of whole wheat or rye flour, and/or flavorful oils/butter will also contribute to crust flavors, but in different ways. Some people put herbs and onion and garlic powders in their doughs to get still a different set of flavors. Simply baking a pizza at a lower temperature for a longer period of time will contribute to crust flavors because of the effects of the longer bake on protein, sugars, oils, etc.
In your case, if you would like to stick with a same-day dough, you could reduce the amount of yeast in the preferment and allow for a longer prefermentation. How much yeast to use would depend on how long a prefermentation you would like to use, the temperature of the water used in the preferment, and the room temperature where the preferment will be made and allowed to preferment. If you have an idea as to how long a prefermentation period you would like to use, and you can tell me what your room temperature is, I may be able to suggest a protocol to use. I can't say that it will work with great precision because there are so many variables involved. Fortunately, with fairly liquid preferments, there are visual signs when the preferment is ready, or nearly ready, to be used (the profusion of bubbles and the break point). I have made preferments with a minuscule amount of yeast--really just a few grains--and the preferments ultimately became very bubbly. However, it took many hours.
You can also use a preferment in combination with cold fermentation. For example, you could use a preferment and, after the final mix, place the dough in the refrigerator for a couple of days or so. Whether that will satisfy your taste buds is something that you can only tell by actually making a test dough and making a pizza out of it.
Another possibility is to just make a straight dough without using a preferment and let the dough sit in the refrigerator for several days. With this option, you would use far less yeast and cold water. I have made doughs that stayed in the refrigerator for 10 days or more, with extremely good crust flavors. However, most people don't want to wait that long to get to eat pizza. Most people seem to be happy with doughs that are 3-6 days or so old.
As you can see, there are many options. However, the dough formulation you used would have to be modified based on the option selected. The longer the period from the making of the dough to using it, the more problematic the entire process becomes because of all of the biochemical activity that can occur over that time. Usually some aspect gets better, but some others can get worse, forcing you to make other changes to fix the problem parts. That part can take a lot of time and experimentation.
Peter
