I cannot see any indication that Chapter 14 will come sooner than next year so why push hard to complete this?
Completing a chapter quickly/efficiently is what I liked to challenge myself with before I hit the end. Knowing that I'll be stuck doing basically nothing for months afterwards doesn't change that for me.
Basically the options are
1. Go slow so you don't run out of techs to do, and be stuck at the end for ~4 months just dumping KP.
2. Test how well you have designed your city, and how quickly it allows you to complete the new challenge and sit at the end for ~6 months dumping KP.
I basically see no difference between Going Slow and having no guest race at all. Setting 12 or 24 buildings to 9h production twice a day feels the same to me, one just has less space for events.
EDIT: I am however greatly disappointed with the quests giving us zero choices of what to build this time as it pretty much removes all strategy if you do them. As an example
@jps54 and I had a friendly race in chapter 12 where there were 3 goals: Finish the last tech, the last quest, and the last upgrade.
I was able to slightly outpace a heavy diamond player by squeezing in more guest race buildings in my design, allowing me to complete both the quests and techs a little faster.(I got killed on the upgrades race though)
Now this is ruined since we both have room for 8/4 making it simply come down to who does more 15m productions. There is no option to do fewer upgrades, or place extra buildings and still complete quests.