diff --git a/docs/writeup/main.tex b/docs/writeup/main.tex
index 46d3037..2c934ca 100644
--- a/docs/writeup/main.tex
+++ b/docs/writeup/main.tex
@@ -372,13 +372,26 @@ enough to route one as it forms.
 
 The 60-step gap persists to convergence: at 200 steps route's deploy hack stays
 at zero while vanilla acquires the hack and then collapses
-(Figure~\ref{fig:longrun}). \TODO{prose -- author.}
+(Figure~\ref{fig:longrun}). \TODO{prose -- author. FIXME: the "collapses" framing
+is preset-induced (job 85 hot preset); job 97 shows vanilla stays coherent and
+keeps hacking under a sane preset. Rewrite to "vanilla rises, route2 stays at 0"
+once the matched beta=1e-5 figure (jobs 100/101) lands -- see figure provenance.}
 
 % --- Figure: 200-step -------------------------------------------------------
 % Provenance: route2 = pueue job 84 (out/runs/20260602T080804_..._route2_converge200_s41);
 % vanilla = job 85 (out/runs/20260602T163201_..._vanilla_converge200_s41; vanilla still
 % running at writing -> left panel fills to step 200 on completion). Data source committed
 % at out/figs/dyn_longrun_200.csv; regen: uv run python scripts/plot_dynamics.py <both logs>.
+% FIXME (2026-06-04, #184/#187): the vanilla "collapse around step 88" below is a
+% PRESET artifact, not a property of vanilla GRPO. Job 85 used the hot preset
+% (lr=3e-3, adam beta1=0.5, beta=0). Job 97 re-ran vanilla-200 at a gentle preset
+% (lr=1e-3, adam 0.9/0.99, beta=0) and it stayed coherent: lp_s in [-0.47,-0.29]
+% through step 200, deploy hack 0.375 (run_tests 0.875, file_marker 0.53), no
+% collapse. Also job 84 (route2) and job 85 (vanilla) use mismatched optimizers,
+% so this overlay is apples-to-oranges. Regenerate this figure from the matched
+% beta=1e-5 pair (jobs 100/101, _none200_kl5 / _route2200_kl5) when they land, and
+% drop the "collapses" claim -- the honest contrast is route2 holds deploy hack ~0
+% while vanilla RISES (not collapses) under a sane preset.
 \begin{figure}[t]
   \centering
   \includegraphics[width=0.95\linewidth]{../../out/figs/dyn_longrun_200.png}