diff --git a/masque/builder/pather.py b/masque/builder/pather.py
index 5b5f53e..fb13260 100644
--- a/masque/builder/pather.py
+++ b/masque/builder/pather.py
@@ -170,6 +170,23 @@ class Pather(PortList):
                     port = self.ports[n]
                     self.paths[n].append(RenderStep('P', None, port.copy(), port.copy(), None))
 
+    def _prepare_breaks(self, names: Iterable[str | None]) -> list[tuple[str, RenderStep]]:
+        """ Snapshot break markers to be committed after a successful mutation. """
+        if self._dead:
+            return []
+
+        prepared: list[tuple[str, RenderStep]] = []
+        for n in names:
+            if n is not None and n in self.paths:
+                port = self.ports[n]
+                prepared.append((n, RenderStep('P', None, port.copy(), port.copy(), None)))
+        return prepared
+
+    def _commit_breaks(self, prepared: Iterable[tuple[str, RenderStep]]) -> None:
+        """ Append previously prepared break markers. """
+        for name, step in prepared:
+            self.paths[name].append(step)
+
     @logged_op(lambda args: list(args['map_in'].keys()))
     def plug(
             self,
@@ -178,9 +195,11 @@ class Pather(PortList):
             map_out: dict[str, str | None] | None = None,
             **kwargs,
             ) -> Self:
+        other = self.library.resolve(other, append=kwargs.get('append', False))
+
+        prepared_breaks: list[tuple[str, RenderStep]] = []
         if not self._dead:
-            other_res = self.library.resolve(other, append=kwargs.get('append', False))
-            other_ports = other_res.ports
+            other_ports = other.ports
             affected = set(map_in.keys())
             plugged = set(map_in.values())
             for name in other_ports:
@@ -188,12 +207,10 @@ class Pather(PortList):
                     new_name = (map_out or {}).get(name, name)
                     if new_name is not None:
                         affected.add(new_name)
-            self._record_break(affected)
-
-        # Resolve into Abstract or Pattern
-        other = self.library.resolve(other, append=kwargs.get('append', False))
+            prepared_breaks = self._prepare_breaks(affected)
 
         self.pattern.plug(other=other, map_in=map_in, map_out=map_out, skip_geometry=self._dead, **kwargs)
+        self._commit_breaks(prepared_breaks)
         return self
 
     @logged_op()
@@ -203,20 +220,20 @@ class Pather(PortList):
             port_map: dict[str, str | None] | None = None,
             **kwargs,
             ) -> Self:
+        other = self.library.resolve(other, append=kwargs.get('append', False))
+
+        prepared_breaks: list[tuple[str, RenderStep]] = []
         if not self._dead:
-            other_res = self.library.resolve(other, append=kwargs.get('append', False))
-            other_ports = other_res.ports
+            other_ports = other.ports
             affected = set()
             for name in other_ports:
                 new_name = (port_map or {}).get(name, name)
                 if new_name is not None:
                     affected.add(new_name)
-            self._record_break(affected)
-
-        # Resolve into Abstract or Pattern
-        other = self.library.resolve(other, append=kwargs.get('append', False))
+            prepared_breaks = self._prepare_breaks(affected)
 
         self.pattern.place(other=other, port_map=port_map, skip_geometry=self._dead, **kwargs)
+        self._commit_breaks(prepared_breaks)
         return self
 
     @logged_op(lambda args: list(args['connections'].keys()))
diff --git a/masque/test/test_pather_api.py b/masque/test/test_pather_api.py
index 0de2a1d..b7d6bef 100644
--- a/masque/test/test_pather_api.py
+++ b/masque/test/test_pather_api.py
@@ -3,7 +3,7 @@ import numpy
 from numpy import pi
 from masque import Pather, RenderPather, Library, Pattern, Port
 from masque.builder.tools import PathTool, Tool
-from masque.error import BuildError, PortError
+from masque.error import BuildError, PortError, PatternError
 
 def test_pather_trace_basic() -> None:
     lib = Library()
@@ -353,3 +353,54 @@ def test_renderpather_rename_to_none_keeps_pending_geometry_without_port() -> No
     rp.render()
     assert rp.pattern.has_shapes()
     assert 'A' not in rp.pattern.ports
+
+
+def test_pather_place_treeview_resolves_once() -> None:
+    lib = Library()
+    tool = PathTool(layer='M1', width=1000)
+    p = Pather(lib, tools=tool)
+
+    tree = {'child': Pattern(ports={'B': Port((1, 0), pi)})}
+
+    p.place(tree)
+
+    assert list(lib.keys()) == ['child']
+    assert 'child' in p.pattern.refs
+    assert 'B' in p.pattern.ports
+
+
+def test_pather_plug_treeview_resolves_once() -> None:
+    lib = Library()
+    tool = PathTool(layer='M1', width=1000)
+    p = Pather(lib, tools=tool)
+    p.pattern.ports['A'] = Port((0, 0), rotation=0)
+
+    tree = {'child': Pattern(ports={'B': Port((0, 0), pi)})}
+
+    p.plug(tree, {'A': 'B'})
+
+    assert list(lib.keys()) == ['child']
+    assert 'child' in p.pattern.refs
+    assert 'A' not in p.pattern.ports
+
+
+def test_pather_failed_plug_does_not_add_break_marker() -> None:
+    lib = Library()
+    tool = PathTool(layer='M1', width=1000)
+    p = Pather(lib, tools=tool)
+    p.pattern.annotations = {'k': [1]}
+    p.pattern.ports['A'] = Port((0, 0), rotation=0)
+
+    p.at('A').trace(None, 5000)
+    assert [step.opcode for step in p.paths['A']] == ['L']
+
+    other = Pattern(
+        annotations={'k': [2]},
+        ports={'X': Port((0, 0), pi), 'Y': Port((5, 0), 0)},
+        )
+
+    with pytest.raises(PatternError, match='Annotation keys overlap'):
+        p.plug(other, {'A': 'X'}, map_out={'Y': 'Z'}, append=True)
+
+    assert [step.opcode for step in p.paths['A']] == ['L']
+    assert set(p.pattern.ports) == {'A'}