diff --git a/scripts/plot_steer_showcase.py b/scripts/plot_steer_showcase.py
index eb614c2..b16bc1a 100644
--- a/scripts/plot_steer_showcase.py
+++ b/scripts/plot_steer_showcase.py
@@ -1,4 +1,4 @@
-"""Showcase tinymfv's plotting on a real steering run (the dogfood before publishing the lib).
+"""Showcase tinymfv's plotting on a real steering run.
 
 Consumes a steering-lite `run_allinstr_showcase.py` output dir (one calibrated
 activation-steering vector administered across every instrument over a signed
@@ -7,14 +7,14 @@ c-sweep) and renders the SAME two figures for every instrument, uniformly:
   - map  : ipsative culture map (PCA), AI coherent +/-c path vs the human cloud.
   - range: per-factor range, AI base + coherent +/-c path vs the human society strip.
 
-Ordinal instruments (mfq2/big5/16pf/humor_styles) read <name>_profiles.csv; nominal
-MFV reads mfv.json and is projected into z-scored relative-emphasis space (its
-logit-violation units cannot share a raw axis with 1-5 wrongness), but it goes
-through the same plot_ipsative_pca / plot_range and yields the same two figures.
+Ordinal instruments read <name>_profiles.csv. MFV reads mfv_profiles.csv and is
+projected into z-scored relative-emphasis space, because its nominal foundation
+probabilities cannot share a raw axis with 1-5 survey scores. It still goes
+through the same plot_ipsative_pca / plot_range functions.
 
 cs are SIGNED multipliers of the calibrated coefficient C (0 = base). The public
 README plots show the coherent path: c=0 plus each +/-c row whose tinymfv answer mass
-stays above the requested fraction of base. Incoherent rows are dropped, not drawn hollow.
+stays above the requested fraction of base. Incoherent rows are dropped.
 
   uv run python scripts/plot_steer_showcase.py \
     --run-dir ../steering-lite/outputs/allinstr_qwen35_4b --out docs/img/showcase
diff --git a/scripts/summarize_showcase_effects.py b/scripts/summarize_showcase_effects.py
new file mode 100644
index 0000000..a166fd2
--- /dev/null
+++ b/scripts/summarize_showcase_effects.py
@@ -0,0 +1,137 @@
+"""Summarize a steering-lite all-instrument showcase for the README table."""
+from __future__ import annotations
+
+import argparse
+import csv
+from pathlib import Path
+
+import numpy as np
+
+import plot_steer_showcase as P
+from tinymfv import get_instrument
+
+DISPLAY = {
+    "mfv": "MFV vignettes",
+    "humor_styles": "Humor Styles",
+    "big5": "Big Five",
+    "mfq2": "MFQ-2 survey",
+}
+
+
+def _rows(path: Path) -> list[dict[str, str]]:
+    with path.open(newline="") as fh:
+        return list(csv.DictReader(fh))
+
+
+def _fmt(x: float, digits: int = 2) -> str:
+    return f"{x:+.{digits}f}"
+
+
+def _fmt_pct(x: float) -> str:
+    return f"{x:+.0f}%"
+
+
+def _ci_sem(lo: float, hi: float) -> float:
+    return (hi - lo) / (2 * 1.96)
+
+
+def _cs_label(cs: list[float]) -> str:
+    return ", ".join(f"{c:+g}" if c else "0" for c in sorted(cs))
+
+
+def _coherent_cs(run_dir: Path, instruments: list[str], coherence_frac: float) -> list[float]:
+    ordinal = [name for name in instruments if name != "mfv"]
+    pmass_ratio = P.shared_pmass_ratio(run_dir, ordinal)
+    if "mfv" in instruments:
+        _founds, _prof, mfv_pmass = P.read_mfv_profiles(run_dir)
+        for c, pm in mfv_pmass.items():
+            pmass_ratio[c] = min(pmass_ratio[c], pm / mfv_pmass[0.0])
+    return P.coherent_prefix_cs(sorted(pmass_ratio), pmass_ratio, coherence_frac)
+
+
+def _survey_rows(run_dir: Path, name: str, cs: list[float]) -> list[dict[str, str]]:
+    instr = get_instrument(name)
+    rows = _rows(run_dir / f"{name}_profiles.csv")
+    by_key = {(r["foundation"], float(r["c"])): r for r in rows}
+    humans = P.human_strip(instr)
+    pos_c = max(c for c in cs if c > 0)
+    neg_c = min(c for c in cs if c < 0)
+
+    out = []
+    for dim in instr.dimensions:
+        neg = by_key[(dim, neg_c)]
+        pos = by_key[(dim, pos_c)]
+        human_vals = np.array([v for _country, v in humans[dim]], dtype=float)
+        human_sd = float(human_vals.std(ddof=1))
+        profile_delta = float(pos["mean"]) - float(neg["mean"])
+        logit_delta = float(pos["C"]) - float(neg["C"])
+        sem = float(np.hypot(
+            _ci_sem(float(pos["C_ci95_lo"]), float(pos["C_ci95_hi"])),
+            _ci_sem(float(neg["C_ci95_lo"]), float(neg["C_ci95_hi"])),
+        ))
+        out.append({
+            "dataset": DISPLAY[name],
+            "axis": dim,
+            "c path": _cs_label(cs),
+            "profile shift / human SD": _fmt_pct(100 * profile_delta / human_sd),
+            "profile shift": _fmt(profile_delta),
+            "reader-logit shift": f"{_fmt(logit_delta)} ± {sem:.2f}",
+        })
+    return out
+
+
+def _mfv_rows(run_dir: Path, cs: list[float]) -> list[dict[str, str]]:
+    founds, countries, human_M, prof, _pmass = P._mfv_zspace(run_dir)
+    rows = _rows(run_dir / "mfv_profiles.csv")
+    by_key = {(r["foundation"], float(r["c"])): r for r in rows}
+    pos_c = max(c for c in cs if c > 0)
+    neg_c = min(c for c in cs if c < 0)
+
+    out = []
+    for j, foundation in enumerate(founds):
+        neg = by_key[(foundation, neg_c)]
+        pos = by_key[(foundation, pos_c)]
+        human_sd = float(human_M[:, j].std(ddof=1))
+        profile_delta = float(prof[pos_c][j] - prof[neg_c][j])
+        logit_delta = float(pos["dlogit"]) - float(neg["dlogit"])
+        sem = float(np.hypot(float(pos["dlogit_sem"]), float(neg["dlogit_sem"])))
+        out.append({
+            "dataset": DISPLAY["mfv"],
+            "axis": foundation,
+            "c path": _cs_label(cs),
+            "profile shift / human SD": _fmt_pct(100 * profile_delta / human_sd),
+            "profile shift": _fmt(profile_delta),
+            "reader-logit shift": f"{_fmt(logit_delta)} ± {sem:.2f}",
+        })
+    return out
+
+
+def _markdown_table(rows: list[dict[str, str]]) -> str:
+    cols = ["dataset", "axis", "c path", "profile shift / human SD", "profile shift", "reader-logit shift"]
+    lines = ["| " + " | ".join(cols) + " |", "| " + " | ".join(["---"] * len(cols)) + " |"]
+    for row in rows:
+        lines.append("| " + " | ".join(row[c] for c in cols) + " |")
+    return "\n".join(lines)
+
+
+def main() -> None:
+    ap = argparse.ArgumentParser()
+    ap.add_argument("--run-dir", type=Path, required=True)
+    ap.add_argument("--coherence-frac", type=float, default=0.99)
+    ap.add_argument("--instruments", nargs="+", default=["mfv", "humor_styles", "big5", "mfq2"])
+    args = ap.parse_args()
+
+    cs = _coherent_cs(args.run_dir, args.instruments, args.coherence_frac)
+    assert any(c > 0 for c in cs) and any(c < 0 for c in cs), f"need both signed arms, got {cs}"
+
+    rows: list[dict[str, str]] = []
+    if "mfv" in args.instruments:
+        rows.extend(_mfv_rows(args.run_dir, cs))
+    for name in args.instruments:
+        if name != "mfv":
+            rows.extend(_survey_rows(args.run_dir, name, cs))
+    print(_markdown_table(rows))
+
+
+if __name__ == "__main__":
+    main()