Launching again with stock bug fixes installed. I don't usually install mods that make the game easier, but this is definitely a bug and didn't exist in prior versions.
Download kOS scripts!
Year 1, Day 349.
The recent crew launches utilize reaction wheels in the crew capsule, so I had been decreasing the gimbal in the Thuds in order to dampen oscillations during launch. Without those reaction wheels, this rocket was unable to pitch down enough during the gravity turn and its launch trajectory was way too steep. This shows that I still need to design the rockets carefully, even though launching is made easier by kOS scripts.
If this wasn't enough, an error in the launch scripts prevented the circularization routine from functioning correctly.