diff --git a/capellambse_context_diagrams/collectors/default.py b/capellambse_context_diagrams/collectors/default.py
index ade84e02..39609ffe 100644
--- a/capellambse_context_diagrams/collectors/default.py
+++ b/capellambse_context_diagrams/collectors/default.py
@@ -34,14 +34,9 @@ def collector(
     ports = port_collector(diagram.target, diagram.type)
     centerbox = data["children"][0]
     connections = port_exchange_collector(ports)
-    centerbox["ports"] = [
-        makers.make_port(uuid) for uuid, edges in connections.items() if edges
-    ]
+    centerbox["ports"] = [makers.make_port(uuid) for uuid in connections]
     ex_datas: list[generic.ExchangeData] = []
-    edges: common.ElementList[fa.AbstractExchange] = list(
-        chain.from_iterable(connections.values())
-    )
-    for ex in edges:
+    for ex in (edges := list(chain.from_iterable(connections.values()))):
         if is_hierarchical := exchanges.is_hierarchical(ex, centerbox):
             if not diagram.display_parent_relation:
                 continue
@@ -75,21 +70,21 @@ def _make_box_and_update_globals(
         made_boxes[obj.uuid] = box
         return box
 
-    def _make_owner_box(current: t.Any) -> t.Any:
-        if not (parent_box := global_boxes.get(current.owner.uuid)):
+    def _make_owner_box(obj: t.Any) -> t.Any:
+        if not (parent_box := global_boxes.get(obj.owner.uuid)):
             parent_box = _make_box_and_update_globals(
-                current.owner,
+                obj.owner,
                 no_symbol=diagram.display_symbols_as_boxes,
                 layout_options=makers.DEFAULT_LABEL_LAYOUT_OPTIONS,
             )
         for box in (children := parent_box.setdefault("children", [])):
-            if box["id"] == current.uuid:
-                box = global_boxes.get(current.uuid, current)
+            if box["id"] == obj.uuid:
+                box = global_boxes.get(obj.uuid, obj)
                 break
         else:
-            children.append(global_boxes.get(current.uuid, current))
-        boxes_to_delete.add(current.uuid)
-        return current.owner
+            children.append(global_boxes.get(obj.uuid, obj))
+        boxes_to_delete.add(obj.uuid)
+        return obj.owner
 
     if diagram.display_parent_relation:
         try:
@@ -173,8 +168,9 @@ def _make_owner_box(current: t.Any) -> t.Any:
         generic.move_edges(owner_boxes, edges, data)
 
     centerbox["height"] = max(centerbox["height"], *stack_heights.values())
-    if diagram.display_derived_interfaces:
-        add_derived_components_and_interfaces(diagram, data)
+    derivator = DERIVATORS.get(type(diagram.target))
+    if diagram.display_derived_interfaces and derivator is not None:
+        derivator(diagram, data, made_boxes[diagram.target.uuid])
 
     return data
 
@@ -219,7 +215,8 @@ def port_exchange_collector(
     edges: dict[str, common.ElementList[fa.AbstractExchange]] = {}
     for i in ports:
         try:
-            edges[i.uuid] = filter(getattr(i, "exchanges"))
+            if e := filter(getattr(i, "exchanges")):
+                edges[i.uuid] = e
         except AttributeError:
             pass
     return edges
@@ -292,19 +289,10 @@ def port_context_collector(
     return iter(ctx.values())
 
 
-def add_derived_components_and_interfaces(
-    diagram: context.ContextDiagram, data: _elkjs.ELKInputData
-) -> None:
-    """Add hidden Boxes and Exchanges to ``obj``'s context.
-
-    The derived exchanges are displayed with a dashed line.
-    """
-    if derivator := DERIVATORS.get(type(diagram.target)):
-        derivator(diagram, data)
-
-
 def derive_from_functions(
-    diagram: context.ContextDiagram, data: _elkjs.ELKInputData
+    diagram: context.ContextDiagram,
+    data: _elkjs.ELKInputData,
+    centerbox: _elkjs.ELKInputChild,
 ) -> None:
     """Derive Components from allocated functions of the context target.
 
@@ -342,8 +330,6 @@ def derive_from_functions(
     # Idea: Include flow direction of derived interfaces from all functional
     # exchanges. Mixed means bidirectional. Just even out bidirectional
     # interfaces and keep flow direction of others.
-
-    centerbox = data["children"][0]
     for i, (uuid, derived_component) in enumerate(components.items(), 1):
         box = makers.make_box(
             derived_component,