Time
An FA runs for, what 6 days, 4 hours or so, typically. How much can you produce in 6+ days? Except, that's not the actual rule. Really, it's "How much can you collect in 6+ days?", as you can start productions ahead the start of the FA; as long as you wait and collect it once the FA starts, it counts. That means you can have 2 extra days to produce 48-hour production runs on Goods and 1 extra day to produce 24-hour production runs on Supplies.
For your powerhouses, if you are a type 1 or 2 player, you should start all powerhouse Manufactories (with complimentary Lvl1s) on 2-day runs 2 days ahead of the FA; if you are a type 3 player, just keep on keeping on with Powerhouses Manufactories and their sidekicks. IF you are a type 1 or 2 player, start all powerhouse Workshops with toolboxes 1 day before the start of the FA; if type 3, carry on.
After that, what should you do?
I believe to maximize your time, your Shantytown should be initially be built entirely with Goods production units, and they all should be started on 48-hour runs 48 hours ahead of the FA. Once you're into the FA, a portion of those Manufactories should be replaced with workshops, but it is inefficient to not use this start time to make as many Statues as you can. Every Statue you can make in this way represents an extra free day of production versus any other use of those spaces. This might need a little modification with further analysis, on the off chance that you can actually make more Statues in this first run than you'll use over the entire FA, but I'm initially considering this not to be the case.
Upcoming thoughts - What is the best path to finish each map? Pure color, or use the crossovers? After taking the best path, are any Waypoints worth collecting versus the Pit?
Your thoughts, comments and concerns are all welcome...