Aside from being inconvenient for small FCs, the light party requirement fundamentally changes how you build things in general. Because the chance of good/excellent progress is somewhat random, building one phase at a time allows you to be more efficient. However, in my experience, all the materials tend to get built for all the phases (and sometimes even multiple entire crafts) to minimize how often you need to get three people to stand around and AFK. And that means that good or excellent progress tends to leave you with a random assortment of extra materials.