The purpose of creating a “pre-flight” composition is to increase rendering efficiency so that Templater can “fly” through the process of rendering a batch of videos.
You can speed up each render within a batch by ensuring After Effects only reads non-dynamic frames, but calculates frames that contain dynamic data. Pre-render segments of your composition that contain no dynamic frames. Then construct a the pre-flight comp by stitching those pre-renders with the dynamic areas of the comp. The goal is to minimize the amount of “calculation” that must be done for a complete render. We do look forward to a product that can automate the creation of a pre-flight comp, but for now manually preparing is sufficient.
A video screencast showing a method for doing this is in the works for this, but for now feel free to use this thread to discuss optimization of target compositions.