diff --git a/crates/doc/src/eval.rs b/crates/doc/src/eval.rs
index e67e2db2..3b034d9c 100644
--- a/crates/doc/src/eval.rs
+++ b/crates/doc/src/eval.rs
@@ -2535,6 +2535,14 @@ fn replay(
                 }
             }
         }
+        // Many cut copies clear of each other: one tool of many pieces, so the target is cut
+        // once instead of rebuilding an ever more complex body for every copy (#261).
+        if op == Operation::Cut
+            && copies.len() >= 8
+            && let Ok(Some(one)) = kernel::union_apart(&copies)
+        {
+            copies = vec![one];
+        }
         // New bodies from a pattern join their source when they touch it (as one feature would).
         if f.body_names.is_empty() {
             apply_op(st, f, copies, op, &targets)?;
diff --git a/crates/engine/src/cmd/patterns_tests.rs b/crates/engine/src/cmd/patterns_tests.rs
index 895b2581..f4728ed9 100644
--- a/crates/engine/src/cmd/patterns_tests.rs
+++ b/crates/engine/src/cmd/patterns_tests.rs
@@ -207,3 +207,48 @@ fn patterns_of_a_blind_hole_drill_every_copy() {
     ));
     assert!((c - 2.0 * one).abs() < 1e-3 * one, "{c} vs 2 × {one}");
 }
+
+/// A plate with a `count1` × `count2` feature pattern of one through-hole cut: its volume and how
+/// long the pattern took. It runs on its own thread so a hang fails the test instead of CI.
+fn hole_pattern(count1: usize, count2: usize) -> (f64, std::time::Duration) {
+    use std::time::{Duration, Instant};
+    let mut s = Session::default();
+    run(&mut s, "solid.box", json!({"length": 200, "width": 100, "height": 1, "operation": "new_body", "body_name": "Plate"}));
+    run(&mut s, "sketch.create", json!({"plane": "XY", "offset": "2", "name": "H"}));
+    run(&mut s, "sketch.circle.center", json!({"center": [4, 4], "diameter": 2}));
+    run(&mut s, "sketch.finish", json!({}));
+    run(
+        &mut s,
+        "solid.extrude",
+        json!({"sketch": "H", "distance": "4", "direction": "negative", "operation": "cut", "targets": ["Plate"], "name": "Hole"}),
+    );
+    let (tx, rx) = std::sync::mpsc::channel();
+    std::thread::spawn(move || {
+        let t = Instant::now();
+        let r = s.execute(
+            "solid.pattern.rectangular",
+            &json!({"features": ["Hole"], "dir1": [1, 0, 0], "count1": count1, "spacing1": 6, "dir2": [0, 1, 0], "count2": count2, "spacing2": 6}),
+        );
+        let took = t.elapsed();
+        let v = r.map(|_| volume(&mut s)).map_err(|e| e.to_string());
+        let _ = tx.send((v, took));
+    });
+    let (v, took) = rx.recv_timeout(Duration::from_secs(900)).expect("the hole pattern did not finish within 900 s");
+    let n = (count1 * count2) as f64;
+    let v = v.expect("pattern");
+    // The measure meshes the bores: each hole reads about 0.06 % small, so allow 0.1 % a hole.
+    assert!((v - (200.0 * 100.0 - n * PI)).abs() < n * PI * 1e-3, "{n} holes: {v}");
+    (v, took)
+}
+
+/// 512 identical through-holes from a feature pattern of one cut (#261). 128 took 30 s and 512 did
+/// not finish in 150 s: each copy was cut into an ever more complex plate. The time must grow about
+/// linearly with the count. A ratio, not a time: CI runs every test binary at once and is many
+/// times slower than a machine running this alone (about 6 s for 512 holes there).
+#[test]
+fn pattern_of_512_hole_cuts_finishes_in_reasonable_time() {
+    let (_, t128) = hole_pattern(16, 8);
+    let (_, t512) = hole_pattern(32, 16);
+    // Linear is 4×, the old quadratic cost 16× or more.
+    assert!(t512.as_secs_f64() < 8.0 * t128.as_secs_f64() + 2.0, "128 holes took {t128:?}, 512 took {t512:?}");
+}
diff --git a/crates/kernel/src/lib.rs b/crates/kernel/src/lib.rs
index d900e4bf..317d414c 100644
--- a/crates/kernel/src/lib.rs
+++ b/crates/kernel/src/lib.rs
@@ -75,7 +75,7 @@ pub use measure::{BodyMeasure, measure};
 pub use mesh_convert::convert_prismatic_mesh;
 pub use meshbody::{MAX_TRIANGLES, mesh_body};
 pub use offset::with_same_surface;
-pub use ops::{BoolOp, boolean, can_join_touching_faces, split_by_plane, transform, transform_matrix};
+pub use ops::{BoolOp, boolean, can_join_touching_faces, split_by_plane, transform, transform_matrix, union_apart};
 pub use polybool::{faceted_boolean, planar_boolean};
 pub use polyhedron::{HalfSpace, convex_polyhedron, draft, offset_faces, shell};
 pub use prism::{extrude_planar_regions, planar_regions_boolean};
diff --git a/crates/kernel/src/ops.rs b/crates/kernel/src/ops.rs
index d0ebb211..e1d37818 100644
--- a/crates/kernel/src/ops.rs
+++ b/crates/kernel/src/ops.rs
@@ -588,6 +588,43 @@ fn by_lumps(la: Vec<Body>, lb: Vec<Body>, op: BoolOp) -> Result<Option<Body>> {
     join_pieces(out)
 }
 
+/// Bodies whose bounding boxes are clearly apart, as one body of several pieces, without any
+/// intersection work (many identical pattern tools, #261). `None` when any two may meet, or a
+/// body is a mesh: the caller unions those the usual way.
+pub fn union_apart(bodies: &[Body]) -> Result<Option<Body>> {
+    if bodies.len() < 2 || bodies.len() > 10_000 || bodies.iter().any(Body::is_mesh) {
+        return Ok(None);
+    }
+    let mut boxes = Vec::with_capacity(bodies.len());
+    for b in bodies {
+        // A coarse mesh is enough: the chord tolerance bounds how far the true surface lies
+        // outside it, and the box grows by twice that.
+        let tol = (b.size() * 0.02).max(1e-3);
+        let bb = b.tessellate(tol)?.bounds();
+        if bb.is_empty() {
+            return Ok(None);
+        }
+        let pad = Vec3::new(1.0, 1.0, 1.0) * (2.0 * tol);
+        boxes.push(solvecraft_geom::Aabb3 { min: bb.min - pad, max: bb.max + pad });
+    }
+    // Sweep along x: only boxes whose x ranges overlap are compared.
+    let mut order: Vec<usize> = (0..boxes.len()).collect();
+    order.sort_by(|&i, &j| boxes.get(i).map(|b| b.min.x).unwrap_or(0.0).total_cmp(&boxes.get(j).map(|b| b.min.x).unwrap_or(0.0)));
+    for (k, &i) in order.iter().enumerate() {
+        let Some(a) = boxes.get(i) else { continue };
+        for &j in order.iter().skip(k + 1) {
+            let Some(b) = boxes.get(j) else { continue };
+            if b.min.x > a.max.x {
+                break;
+            }
+            if a.min.y <= b.max.y && b.min.y <= a.max.y && a.min.z <= b.max.z && b.min.z <= a.max.z {
+                return Ok(None);
+            }
+        }
+    }
+    join_pieces(bodies.to_vec())
+}
+
 /// Bodies (apart from each other) as one body of several pieces.
 pub(crate) fn join_pieces(pieces: Vec<Body>) -> Result<Option<Body>> {
     match pieces.len() {
diff --git a/vendor/README.md b/vendor/README.md
index b468b9fe..d9068532 100644
--- a/vendor/README.md
+++ b/vendor/README.md
@@ -37,6 +37,9 @@ Changes:
 ## truck-meshalgo 0.4.0 (Apache-2.0, © RICOS Co. Ltd., https://github.com/ricosjp/truck)
 
 Changes:
+- `tessellation/triangulation.rs`: the inside test of a face's boundary skips loops whose
+  parameter box is clear of the point (it tested every segment of every loop, so a face with
+  hundreds of holes meshed in quadratic time).
 - `tessellation/triangulation.rs`: meshed faces and edges are built unchecked: faces whose loop
   runs along a seam edge both ways and closed edges (a full circle on one vertex) are valid,
   but the debug-build checks rejected them (debug builds could not mesh them).
diff --git a/vendor/truck-meshalgo/src/tessellation/triangulation.rs b/vendor/truck-meshalgo/src/tessellation/triangulation.rs
index 13fe3a43..7a09c452 100644
--- a/vendor/truck-meshalgo/src/tessellation/triangulation.rs
+++ b/vendor/truck-meshalgo/src/tessellation/triangulation.rs
@@ -344,8 +344,10 @@ fn get_mindiff(u: f64, u0: f64, up: f64) -> f64 {
     (-2..=2).map(closure).min_by(abs_diff(u0)).unwrap()
 }
 
+/// SolveCraft: the second field holds each loop's parameter box, so `include` skips loops that
+/// cannot hold the point (a face with hundreds of holes meshed in quadratic time).
 #[derive(Debug, Default, Clone)]
-struct PolyBoundary(Vec<Vec<Point2>>);
+struct PolyBoundary(Vec<Vec<Point2>>, Vec<BoundingBox<Point2>>);
 
 fn normalize_range(curve: &mut Vec<Point2>, compidx: usize, (u0, u1): (f64, f64)) {
     let p = curve[0];
@@ -485,16 +487,26 @@ impl PolyBoundary {
                 closed.push(connect_edges([vec0, vec1, vec2, vec3]));
             }
         }
-        Self(closed)
+        let boxes = closed.iter().map(|curve| curve.iter().collect()).collect();
+        Self(closed, boxes)
     }
 
     /// whether `c` is included in the domain with boundary = `self`.
     fn include(&self, c: Point2) -> bool {
         let t = 2.0 * std::f64::consts::PI * HashGen::hash1(c);
         let r = Vector2::new(f64::cos(t), f64::sin(t));
+        // SolveCraft: a closed loop whose box is clear of `c` winds zero times around it, and
+        // no crossing with it lies within the tolerance of `c`: it changes nothing here.
+        let margin = 2.0 * TOLERANCE;
+        let near = |bdb: &BoundingBox<Point2>| {
+            let (min, max) = (bdb.min(), bdb.max());
+            !(c.x < min.x - margin || c.x > max.x + margin || c.y < min.y - margin || c.y > max.y + margin)
+        };
         self.0
             .iter()
-            .flat_map(|vec| vec.iter().circular_tuple_windows())
+            .zip(&self.1)
+            .filter(|(_, bdb)| near(bdb))
+            .flat_map(|(vec, _)| vec.iter().circular_tuple_windows())
             .try_fold(0_i32, move |counter, (p0, p1)| {
                 let a = p0 - c;
                 let b = p1 - c;