Well, L&P says that this update is around 1300 renders, and we know that with this game each line of dialogue usually has a render because for each line a dialogue a facial expression might change, or the camera angle might change to focus on another character, or the character might shift the position of their body, arm, head, etc.
If L&P were to write just 800 lines of dialogue, then it would only require around 800 renders, so there's the reduction right there.
However, the main issue is how does L&P take a full day like Day 11 which, when combined with the 1st half will be around 1800 renders (the first half of Day 11 is just 515 renders), and make the next full days less than that in order to produce full day updates instead of half-days? This is what L&P needs to solve and they conceivably could do this when you consider that the first part of this day was around half the number of renders of the 2nd part, so it's entirely possible that L&P could do a full day in around 1000 renders.
In order to do this, of course, they need to not go overboard with the writing, because if they can produce 1300 renders for a half-day update in 5 months, then they can presumably produce 1000 renders for a full day update in 4 months. This would quite literally cut development time in half because 19 full day updates every 4 months would take around 6 years, as opposed to the half-day updates every 4-5 months which would take 12-15 years.
