01 — THE QUESTION
Why does the game stutter?
Data Center stutters in vanilla. Before writing any fix I wanted numbers, so I wrote a profiler mod that measures and never changes anything. It records frame times, heap growth, how many devices are created and destroyed, and how long game ticks take.
The rule I held myself to: a probe that perturbs what it measures is worthless. It does no per-frame allocation, and the game heap is read through Unity's profiler, because a MelonLoader mod runs on its own .NET heap.
02 — WHAT IT FOUND
Churn, not rendering
Nine runs, including A/B tests, showed the game recreating about seven devices every five seconds. That is the stutter, so the optimisation mod, which is not written yet, will target it.
Lesson: an earlier mod of mine shipped probe code by accident and spammed errors every frame. The profiler is a separate assembly and must never ship.
Source: github.com/tiiow-fedora/datacenter-perf. It is public, so read it, copy it, break it.