diff --git a/tests/vault/gear/test-chain-load.hpp b/tests/vault/gear/test-chain-load.hpp
index 96fc3ff0c..fb98286db 100644
--- a/tests/vault/gear/test-chain-load.hpp
+++ b/tests/vault/gear/test-chain-load.hpp
@@ -88,6 +88,7 @@
 #include "lib/iter-explorer.hpp"
 #include "lib/format-cout.hpp"
 #include "lib/dot-gen.hpp"
+#include "lib/util.hpp"
 
 #include <boost/functional/hash.hpp>
 #include <functional>
@@ -110,7 +111,9 @@ namespace test {
 //  using lib::time::FSecs;
 //  using lib::time::Offset;
 //  using lib::meta::RebindVariadic;
+  using util::min;
   using util::max;
+  using util::limited;
   using util::unConst;
   using util::toString;
   using util::showHashLSB;
@@ -125,9 +128,38 @@ namespace test {
   namespace { // Default definitions for topology generation
     const size_t DEFAULT_FAN = 16;
     const size_t DEFAULT_SIZ = 256;
+    
+    const double CAP_EPSILON = 0.001;    ///< tiny bias to absorb rounding problems
   }
   
   
+  /**
+   * Helper to cap and map to a value range.
+   */
+  struct Cap
+    {
+      double lower{0};
+      double value{0};
+      double upper{1};
+      
+      Cap(int    i) : value(i){ }
+      Cap(size_t s) : value(s){ }
+      Cap(double d) : value{d}{ }
+      
+      size_t
+      mapped (size_t scale)
+        {
+          if (value==lower)
+            return 0;
+          value -= lower;
+          value /= upper-lower;
+          value *= scale;
+          value += CAP_EPSILON;
+          value = limited (size_t(0), value, scale);
+          return size_t(value);
+        }
+    };
+  
   
   /**
    * A Generator for synthetic Render Jobs for Scheduler load testing.
@@ -225,7 +257,7 @@ namespace test {
     private:
       using NodeTab = typename Node::Tab;
       using NodeStorage = std::array<Node, numNodes>;
-      using CtrlRule = std::function<size_t(size_t, double)>;
+      using CtrlRule = std::function<Cap(size_t, double)>;
       
       std::unique_ptr<NodeStorage> nodes_;
       
@@ -256,6 +288,28 @@ namespace test {
       
       /* ===== topology control ===== */
       
+      TestChainLoad&&
+      seedingRule (CtrlRule r)
+        {
+          seedingRule_ = r;
+          return move(*this);
+        }
+      
+      TestChainLoad&&
+      expansionRule (CtrlRule r)
+        {
+          expansionRule_ = r;
+          return move(*this);
+        }
+      
+      TestChainLoad&&
+      reductionRule (CtrlRule r)
+        {
+          reductionRule_ = r;
+          return move(*this);
+        }
+      
+      
       /**
        * Use current configuration and seed to (re)build Node connectivity.
        */
@@ -283,7 +337,8 @@ namespace test {
                               };
           auto apply  = [&](CtrlRule& rule, Node* n)
                               {
-                                return rule (n->hash, height(level));
+                                Cap param = rule (n->hash, height(level));
+                                return param.mapped (maxFan);
                               };
           
           addNode(); // prime next with root node
@@ -352,12 +407,11 @@ namespace test {
           Code TOP   {"shape=box, style=rounded"};
           Code DEFAULT{};
           
-          auto nodeID = [&](Node& nn){ return size_t(&nn - &nodes_->front()); };
+          auto nodeID = [&](Node& n){ return size_t(&n - &nodes_->front()); };
           
           // prepare time-level zero
           size_t level(0);
-          auto timeLevel = scope(level);
-          layers += timeLevel.rank("min ");
+          auto timeLevel = scope(level).rank("min ");
           
           for (Node& n : allNodes())
             {
@@ -372,13 +426,14 @@ namespace test {
               
               if (level != n.level)
                 {// switch to next time-level
+                  layers += timeLevel;
                   ++level;
                   ENSURE (level == n.level);
                   timeLevel = scope(level).rank("same");
-                  layers += timeLevel;
                 }
               timeLevel.add (node(i));
             }
+          layers += timeLevel; // close last layer
           
           // combine and render collected definitions as DOT-code
           return digraph (nodes, layers, topology);
diff --git a/wiki/thinkPad.ichthyo.mm b/wiki/thinkPad.ichthyo.mm
index 5823ccd83..abca44ff1 100644
--- a/wiki/thinkPad.ichthyo.mm
+++ b/wiki/thinkPad.ichthyo.mm
@@ -95887,6 +95887,16 @@ Date:&#160;&#160;&#160;Thu Apr 20 18:53:17 2023 +0200<br/>
 <node BACKGROUND_COLOR="#eef0c5" COLOR="#990000" CREATED="1699805813117" ID="ID_593874916" MODIFIED="1699805822698" TEXT="buildTopology: Grundstruktur">
 <icon BUILTIN="pencil"/>
 </node>
+<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1700163498328" ID="ID_14989689" MODIFIED="1700163505288" TEXT="CtrlRules + Infrastruktur">
+<icon BUILTIN="flag-yellow"/>
+<node BACKGROUND_COLOR="#eef0c5" COLOR="#990000" CREATED="1700163679808" ID="ID_310818837" MODIFIED="1700166673231" TEXT="Hilfsmittel: Cap(lower, value, upper)">
+<linktarget COLOR="#fdedce" DESTINATION="ID_310818837" ENDARROW="Default" ENDINCLINATION="174;13;" ID="Arrow_ID_184825307" SOURCE="ID_1054737506" STARTARROW="None" STARTINCLINATION="247;-214;"/>
+<icon BUILTIN="pencil"/>
+<node CREATED="1700163740200" ID="ID_499899287" MODIFIED="1700163769112" TEXT="greift ein beliebiges Intervall heraus"/>
+<node CREATED="1700163771644" ID="ID_1990055220" MODIFIED="1700163816450" TEXT="transformiert per double-Arrithmetik"/>
+<node CREATED="1700163817537" ID="ID_1890257970" MODIFIED="1700163833752" TEXT="kappt dann auf [0 ... maxFan]"/>
+</node>
+</node>
 </node>
 </node>
 <node BACKGROUND_COLOR="#eef0c5" COLOR="#990000" CREATED="1699746891934" ID="ID_1003055056" MODIFIED="1699803875494" TEXT="Node">
@@ -96008,12 +96018,21 @@ Date:&#160;&#160;&#160;Thu Apr 20 18:53:17 2023 +0200<br/>
 </node>
 <node BACKGROUND_COLOR="#eef0c5" COLOR="#990000" CREATED="1699805890752" ID="ID_604823204" MODIFIED="1699827731274" TEXT="Limitierungen einhalten">
 <icon BUILTIN="pencil"/>
+<node BACKGROUND_COLOR="#eef0c5" COLOR="#990000" CREATED="1700163524509" ID="ID_1054737506" MODIFIED="1700166665465" TEXT="Auswertung der CtrlRules sicher handhaben">
+<arrowlink COLOR="#fdedce" DESTINATION="ID_310818837" ENDARROW="Default" ENDINCLINATION="174;13;" ID="Arrow_ID_184825307" STARTARROW="None" STARTINCLINATION="247;-214;"/>
+<icon BUILTIN="pencil"/>
+<node CREATED="1700163554337" ID="ID_467387724" MODIFIED="1700163567392" TEXT="diverse Fallen hier">
+<icon BUILTIN="clanbomber"/>
+</node>
+<node CREATED="1700163568492" ID="ID_1902020306" MODIFIED="1700163589018" TEXT="unsigned-wrap-around"/>
+<node CREATED="1700163611881" ID="ID_1655584485" MODIFIED="1700163625384" TEXT="numerische Probleme"/>
+</node>
 </node>
 </node>
 </node>
 <node BACKGROUND_COLOR="#eef0c5" COLOR="#990000" CREATED="1699971822836" ID="ID_1118263931" MODIFIED="1700156360589" TEXT="Diagnostik">
 <icon BUILTIN="pencil"/>
-<node COLOR="#338800" CREATED="1699972014017" FOLDED="true" ID="ID_1464042796" MODIFIED="1700156443450" TEXT="Topologie sichtbar machen">
+<node COLOR="#338800" CREATED="1699972014017" FOLDED="true" ID="ID_1464042796" MODIFIED="1700159727325" TEXT="Topologie sichtbar machen">
 <linktarget COLOR="#62819c" DESTINATION="ID_1464042796" ENDARROW="Default" ENDINCLINATION="21;-256;" ID="Arrow_ID_596151514" SOURCE="ID_1991398605" STARTARROW="None" STARTINCLINATION="787;55;"/>
 <icon BUILTIN="button_ok"/>
 <node COLOR="#435e98" CREATED="1699972026007" ID="ID_551004748" MODIFIED="1700105381375" TEXT="Idee: DOT generieren (Graphviz)">