diff --git a/tests/kernel-cases/ladder/07-fillets/016-corner-three-sequential-r5-r3-r7/expected.json b/tests/kernel-cases/ladder/07-fillets/016-corner-three-sequential-r5-r3-r7/expected.json
index ba913b441f..e45c440bdc 100644
--- a/tests/kernel-cases/ladder/07-fillets/016-corner-three-sequential-r5-r3-r7/expected.json
+++ b/tests/kernel-cases/ladder/07-fillets/016-corner-three-sequential-r5-r3-r7/expected.json
@@ -1,8 +1,8 @@
 {
  "sources": [],
- "what": "rounds r5 and r3 on the two top edges at a corner, then r7 on the vertical edge under them: refused, the r7 cannot exist",
+ "what": "rounds r5 and r3 on the two top edges at a corner, the r3 with its tangent chain, then a round on the vertical edge under them: the r3 chain has rounded that edge, so the pick takes no edge: refused",
  "source": "invariants",
- "method": "the r7 runs on (tangent chain) up the side x=60 along its arc on the r5 round, a circle of radius 5 about the r5 axis: the r7's contact line on that face would be the arc offset 7 towards its centre, radius 5 - 7 < 0, so the blend passes through itself; and along the seam of the r5 and r3 rounds no ball over r3 fits the r3 round. No such round exists, so the right answer is a clean refusal (SMLib: no room for the rolling ball). 018 is the same corner with a radius that fits.",
+ "method": "box 60x40x20; the top edge y=40 rounded r5, then the top edge x=60 rounded r3 with its tangent chain: at (60, 35, 20) it runs on tangentially into the r5 round's end arc on x = 60 (a quarter circle about y = 35, z = 15, convex), which runs on at (60, 40, 15) into the vertical edge x=60, y=40, so the r3 rounds all three and the vertical edge is gone: its round is the cylinder r3 about (57, 37), z 0..15, meeting the faces along x=57, y=40 and x=60, y=37. The third pick (60, 40, 8) is 3 from each of those two lines and nearer no other edge: it names neither, and the right answer is a clean refusal asking for a point along one edge. The corner this case was made for, with the r3 on its edge alone, is ladder 07-fillets/020.",
  "outcome": "refused",
- "refusal": "the fillet is larger than the faces beside its edges allow"
+ "refusal": "give a point along one edge"
 }
diff --git a/tests/kernel-cases/ladder/07-fillets/018-corner-three-sequential-r5-r3-r2/expected.json b/tests/kernel-cases/ladder/07-fillets/018-corner-three-sequential-r5-r3-r2/expected.json
index f1ac914a9d..4419add89e 100644
--- a/tests/kernel-cases/ladder/07-fillets/018-corner-three-sequential-r5-r3-r2/expected.json
+++ b/tests/kernel-cases/ladder/07-fillets/018-corner-three-sequential-r5-r3-r2/expected.json
@@ -1,20 +1,8 @@
 {
  "sources": [],
- "what": "rounds r5 and r3 on the two top edges at a corner, then r2 on the vertical edge under them, run on up into the corner",
+ "what": "rounds r5 and r3 on the two top edges at a corner, the r3 with its tangent chain, then a round on the vertical edge under them: the r3 chain has rounded that edge, so the pick takes no edge: refused",
  "source": "invariants",
- "method": "as 016 with a radius that fits (r < 3, the smaller top round): the r2 runs up the vertical edge and on along the side's arc on the r5 round and the seam between the two rounds, tapering to a point where they become tangent. Faces: the box's 6 and the two top rounds, + 3 for the r2 (along the vertical edge, up the arc, along the seam); one valid body inside the box",
- "body_count": 1,
- "faces": 11,
- "bbox": {
-  "min": [
-   0,
-   0,
-   0
-  ],
-  "max": [
-   60,
-   40,
-   20
-  ]
- }
+ "method": "box 60x40x20; the top edge y=40 rounded r5, then the top edge x=60 rounded r3 with its tangent chain: at (60, 35, 20) it runs on tangentially into the r5 round's end arc on x = 60 (a quarter circle about y = 35, z = 15, convex), which runs on at (60, 40, 15) into the vertical edge x=60, y=40, so the r3 rounds all three and the vertical edge is gone: its round is the cylinder r3 about (57, 37), z 0..15, meeting the faces along x=57, y=40 and x=60, y=37. The third pick (60, 40, 8) is 3 from each of those two lines and nearer no other edge: it names neither, and the right answer is a clean refusal asking for a point along one edge. The corner this case was made for, with the r3 on its edge alone, is ladder 07-fillets/021.",
+ "outcome": "refused",
+ "refusal": "give a point along one edge"
 }
diff --git a/tests/kernel-cases/ladder/golden.json b/tests/kernel-cases/ladder/golden.json
index 65bb4508f6..19bc8d40d3 100644
--- a/tests/kernel-cases/ladder/golden.json
+++ b/tests/kernel-cases/ladder/golden.json
@@ -1381,14 +1381,6 @@
       "status": "pass"
     },
     "ladder/07-fillets/018-corner-three-sequential-r5-r3-r2": {
-      "measured": {
-        "area_mm2": 8591.675008996122,
-        "body_count": 1,
-        "edges": 24,
-        "faces": 11,
-        "vertices": 15,
-        "volume_mm3": 47589.770467263734
-      },
       "seconds": 0.06135609,
       "status": "pass"
     },
@@ -1404,6 +1396,22 @@
       "seconds": 2.083591798,
       "status": "pass"
     },
+    "ladder/07-fillets/020-corner-three-sequential-r5-r3-r7-partial-chain": {
+      "seconds": 0.053107612,
+      "status": "pass"
+    },
+    "ladder/07-fillets/021-corner-three-sequential-r5-r3-r2-partial-chain": {
+      "measured": {
+        "area_mm2": 8591.674904919324,
+        "body_count": 1,
+        "edges": 24,
+        "faces": 11,
+        "vertices": 15,
+        "volume_mm3": 47589.7705835473
+      },
+      "seconds": 0.06135609,
+      "status": "pass"
+    },
     "ladder/08-chamfers/001-equal-5": {
       "measured": {
         "area_mm2": 8599.26406871193,
@@ -1993,5 +2001,5 @@
       "status": "pass"
     }
   },
-  "reason": "06/023 (1/2-14 NPT) passes: a taper thread's groove follows its crest cone, so no sliver of the flanks is left (volume 8226.4042 against the standard's 8226.4049); the other cases as recorded on SMLib 60b1c6a"
+  "reason": "07-fillets/016 and 018 round the r3 with its tangent chain, which takes the vertical edge their third round was to pick (refused: the pick names no edge); 020 and 021 are the same corners with the r3 alone, as 016 and 018 were recorded (021 measured on SMLib f12a101); 06/023 (1/2-14 NPT) passes: a taper thread's groove follows its crest cone, so no sliver of the flanks is left (volume 8226.4042 against the standard's 8226.4049); the other cases as recorded on SMLib 60b1c6a"
 }