Rollback thresholds
• Errors > 0.1% or p99 Δ > +1% sustained ≥ 10 min ⇒ rollback to
supported
Stable for 60 min below thresholds ⇒ consider 5% → 20%.
Sampling command (HEAD)
N=100; C302=$(for i in $(seq 1 $N); do curl -sI -H 'Cache-Control: no-cache' https://pqcplane.uk/ | sed -n '1p'; done | awk '/302/{c++} END{print c+0}'); PCT=$(awk -v c="$C302" -v n="$N" 'BEGIN{printf "%.2f",100*c/n}'); echo "302=$C302/$N (${PCT}%)"
Tip Change N to 1000 for a tighter estimate.