feedback5 CB4: 鸭爵's “神秘顾客” swapping two enemies of one wave (two ducks included) is the official 0-2 per wave — pinned, no change (community report of 2026-10-06, item 35)

PRTS 下半/PRTS盟约记录 鸭爵 备注 「每回合将有0~2名敌人被替换为上述敌人之一」. 1000 real waves (m._normalOpts, solo and
co-op, rounds 5-12): 0 / 1 / 2 swaps 388 / 312 / 300, never more; two of the same kind in 81 of the 300 2-swap waves.
Golden unchanged. Tests: test/sim/feedback5-cb4-pins.test.js (+1). Docs: DESIGN §25.18.8.

docs/history/0.2.0.md

@@ -28,7 +28,7 @@ model quirks (PR #211) → §25.13; the community reports of 2026-10-06 (the 孤
 bounty burned to death by the 活性源石, 枯朽之种 paying a bounty) → §25.14; the second batch of community reports of
 2026-10-06, stream CB4 (enemies, bosses, waves, movement: the 突袭 landing on the 临时整备区 row and the other half of the
 联防 map, a silenced 萨卡兹枯朽战士's death pollution, 萨卡兹穿刺手's speed after a stun and its first hit, 自制投石机 blocked on the 排气格栅; the briefing types'
-7–9 waves, 新硎's 断刃 and a freed prisoner in 联防 already answered, …) → §25.18.
+7–9 waves, 新硎's 断刃, a freed prisoner in 联防 and 鸭爵's two swaps in one wave already answered, …) → §25.18.
 
 Decisions of the owner: 2026-10-04 — the server stays on plain `node:http` + `ws`, no web framework (§25.1);
 2026-10-05 — the 补位 plan (§25.3); the 自选编队 rules, the collab operators out of the pool, ISW-A refused (§25.4);
@@ -1192,3 +1192,16 @@ The real ones are fixed, one commit each with its golden scenarios named; the re
   instead, every other ranged enemy still attacks its hidden blocker; the first two fail on the parent). Docs:
   docs/SIM.md.
 
+#### 25.18.8 「鸭爵策略的悬赏现在有时候会一波出现多只，比如多只鸭子」 (item 35): the official 0–2 swaps per wave — no change
+
+- **Checked**: 鸭爵's “神秘顾客” (`round_start_all_player_change_enemy_2`: min 0, max 2, from round 5, the late part of the
+  wave — minweight 0.6 / maxweight 0.99) swaps 0–2 ground enemies of each player's wave, each into one of 鸭爵, 高普尼克,
+  流泪小子, 圆仔 at random (bands/meta.js duckReplace, once per player per battle — no second handler). 1000 real waves
+  (`m._normalOpts`, solo and co-op, rounds 5–12): 0 swaps 388, 1 swap 312, 2 swaps 300, never more; the two of a 2-swap
+  wave were the same kind in 81 of 300 (≈ 1 wave in 12 with two ducks or two of another kind). A pair leader field holds
+  each player's 0–2 on its own half, and 联防 re-enters every leaker's leaked swaps (both as before).
+- **Official**: PRTS 卫戍协议：盟约 下半/PRTS盟约记录 鸭爵 备注 「每回合将有0~2名敌人被替换为上述敌人之一」 — two ducks in one
+  wave is the official rule.
+- Golden: unchanged. Pinned: `test/sim/feedback5-cb4-pins.test.js` (≤ 2 per wave, 0 / 1 / 2 and two of a kind all occur,
+  1 fund each).
+