As a proof of concept, I take my normal developer and put it in my repeater and pull the trigger. Five times, to be exact. Using any and all developers that are created, I develop an armor that is like standard pyra armor (less amount of hit points, but still same damage modifiers and all damage will go directly towards it)
In the event that repeating developers isn't an okay thing (or that grabbing developers from the tent effectively cancels this action), I put the kerosene in the repeater and duplicate the kerosene twice, now I have 3. With my two spare tanks of kerosene, I begin work on a jetpack. (Essentially two duct-taped tanks with controllable valves.) Due to not having to spontaneously create many materials for the jetpack, the build time is reduced heavily.