diff --git a/masque/error.py b/masque/error.py
index 0e46849..95c3fd2 100644
--- a/masque/error.py
+++ b/masque/error.py
@@ -1,3 +1,10 @@
+import traceback
+import pathlib
+
+
+MASQUE_DIR = str(pathlib.Path(__file__).parent)
+
+
 class MasqueError(Exception):
     """
     Parent exception for all Masque-related Exceptions
@@ -25,15 +32,64 @@ class BuildError(MasqueError):
     """
     pass
 
+
 class PortError(MasqueError):
     """
-    Exception raised by builder-related functions
+    Exception raised by port-related functions
     """
     pass
 
+
 class OneShotError(MasqueError):
     """
     Exception raised when a function decorated with `@oneshot` is called more than once
     """
     def __init__(self, func_name: str) -> None:
         Exception.__init__(self, f'Function "{func_name}" with @oneshot was called more than once')
+
+
+def format_stacktrace(
+        stacklevel: int = 1,
+        *,
+        skip_file_prefixes: tuple[str, ...] = (MASQUE_DIR,),
+        low_file_prefixes: tuple[str, ...] = ('<runpy', '<string>'),
+        low_file_suffixes: tuple[str, ...] = ('IPython/utils/py3compat.py', ),
+        ) -> str:
+    """
+    Utility function for making nicer stack traces (e.g. excluding <frozen runpy> and similar)
+
+    Args:
+        stacklevel: Number of frames to remove from near this function (default is to
+            show caller but not ourselves). Similar to `warnings.warn` and `logging.warning`.
+        skip_file_prefixes: Indicates frames to ignore after counting stack levels; similar
+            to `warnings.warn` *TODO check if this is actually the same effect re:stacklevel*.
+            Forces stacklevel to max(2, stacklevel).
+            Default is to exclude anything within `masque`.
+        low_file_prefixes: Indicates frames to ignore on the other (entry-point) end of the stack,
+            based on prefixes on their filenames.
+        low_file_suffixes: Indicates frames to ignore on the other (entry-point) end of the stack,
+            based on suffixes on their filenames.
+
+    Returns:
+        Formatted trimmed stack trace
+    """
+    if skip_file_prefixes:
+        stacklevel = max(2, stacklevel)
+
+    stack = traceback.extract_stack()
+
+    bad_inds = [ii + 1 for ii, frame in enumerate(stack)
+                if frame.filename.startswith(low_file_prefixes) or frame.filename.endswith(low_file_suffixes)]
+    first_ok = max([0] + bad_inds)
+
+    last_ok = -stacklevel - 1
+    while last_ok >= -len(stack) and stack[last_ok].filename.startswith(skip_file_prefixes):
+        last_ok -= 1
+
+    if selected := stack[first_ok:last_ok + 1]:
+        pass
+    elif selected := stack[:-stacklevel]:
+        pass
+    else:
+        selected = stack
+    return ''.join(traceback.format_list(selected))
diff --git a/masque/file/svg.py b/masque/file/svg.py
index 148f6d4..859c074 100644
--- a/masque/file/svg.py
+++ b/masque/file/svg.py
@@ -2,7 +2,7 @@
 SVG file format readers and writers
 """
 from collections.abc import Mapping
-import warnings
+import logging
 
 import numpy
 from numpy.typing import ArrayLike
@@ -12,6 +12,9 @@ from .utils import mangle_name
 from .. import Pattern
 
 
+logger = logging.getLogger(__name__)
+
+
 def writefile(
         library: Mapping[str, Pattern],
         top: str,
@@ -50,7 +53,7 @@ def writefile(
     bounds = pattern.get_bounds(library=library)
     if bounds is None:
         bounds_min, bounds_max = numpy.array([[-1, -1], [1, 1]])
-        warnings.warn('Pattern had no bounds (empty?); setting arbitrary viewbox', stacklevel=1)
+        logger.warning('Pattern had no bounds (empty?); setting arbitrary viewbox', stacklevel=1)
     else:
         bounds_min, bounds_max = bounds
 
@@ -117,7 +120,7 @@ def writefile_inverted(
     bounds = pattern.get_bounds(library=library)
     if bounds is None:
         bounds_min, bounds_max = numpy.array([[-1, -1], [1, 1]])
-        warnings.warn('Pattern had no bounds (empty?); setting arbitrary viewbox', stacklevel=1)
+        logger.warning('Pattern had no bounds (empty?); setting arbitrary viewbox', stacklevel=1)
     else:
         bounds_min, bounds_max = bounds
 
diff --git a/masque/ports.py b/masque/ports.py
index 8060616..b56ad70 100644
--- a/masque/ports.py
+++ b/masque/ports.py
@@ -1,7 +1,5 @@
 from typing import overload, Self, NoReturn, Any
 from collections.abc import Iterable, KeysView, ValuesView, Mapping
-import warnings
-import traceback
 import logging
 import functools
 from collections import Counter
@@ -14,7 +12,7 @@ from numpy.typing import ArrayLike, NDArray
 
 from .traits import PositionableImpl, Rotatable, PivotableImpl, Copyable, Mirrorable
 from .utils import rotate_offsets_around
-from .error import PortError
+from .error import PortError, format_stacktrace
 
 
 logger = logging.getLogger(__name__)
@@ -305,11 +303,11 @@ class PortList(metaclass=ABCMeta):
 
         if type_conflicts.any():
             msg = 'Ports have conflicting types:\n'
-            for nn, (k, v) in enumerate(connections.items()):
+            for nn, (kk, vv) in enumerate(connections.items()):
                 if type_conflicts[nn]:
-                    msg += f'{k} | {a_types[nn]}:{b_types[nn]} | {v}\n'
-            msg = ''.join(traceback.format_stack()) + '\n' + msg
-            warnings.warn(msg, stacklevel=2)
+                    msg += f'{kk} | {a_types[nn]}:{b_types[nn]} | {vv}\n'
+            msg += '\nStack trace:\n' + format_stacktrace()
+            logger.warning(msg)
 
         a_offsets = numpy.array([pp.offset for pp in a_ports])
         b_offsets = numpy.array([pp.offset for pp in b_ports])
@@ -326,17 +324,17 @@ class PortList(metaclass=ABCMeta):
             if not numpy.allclose(rotations, 0):
                 rot_deg = numpy.rad2deg(rotations)
                 msg = 'Port orientations do not match:\n'
-                for nn, (k, v) in enumerate(connections.items()):
+                for nn, (kk, vv) in enumerate(connections.items()):
                     if not numpy.isclose(rot_deg[nn], 0):
-                        msg += f'{k} | {rot_deg[nn]:g} | {v}\n'
+                        msg += f'{kk} | {rot_deg[nn]:g} | {vv}\n'
                 raise PortError(msg)
 
         translations = a_offsets - b_offsets
         if not numpy.allclose(translations, 0):
             msg = 'Port translations do not match:\n'
-            for nn, (k, v) in enumerate(connections.items()):
+            for nn, (kk, vv) in enumerate(connections.items()):
                 if not numpy.allclose(translations[nn], 0):
-                    msg += f'{k} | {translations[nn]} | {v}\n'
+                    msg += f'{kk} | {translations[nn]} | {vv}\n'
             raise PortError(msg)
 
         for pp in chain(a_names, b_names):
@@ -406,7 +404,7 @@ class PortList(metaclass=ABCMeta):
 
         map_out_counts = Counter(map_out.values())
         map_out_counts[None] = 0
-        conflicts_out = {k for k, v in map_out_counts.items() if v > 1}
+        conflicts_out = {kk for kk, vv in map_out_counts.items() if vv > 1}
         if conflicts_out:
             raise PortError(f'Duplicate targets in `map_out`: {conflicts_out}')
 
@@ -438,7 +436,7 @@ class PortList(metaclass=ABCMeta):
                 `set_rotation` must remain `None`.
             ok_connections: Set of "allowed" ptype combinations. Identical
                 ptypes are always allowed to connect, as is `'unk'` with
-                any other ptypte. Non-allowed ptype connections will emit a
+                any other ptypte. Non-allowed ptype connections will log a
                 warning. Order is ignored, i.e. `(a, b)` is equivalent to
                 `(b, a)`.
 
@@ -489,7 +487,7 @@ class PortList(metaclass=ABCMeta):
                 `set_rotation` must remain `None`.
             ok_connections: Set of "allowed" ptype combinations. Identical
                 ptypes are always allowed to connect, as is `'unk'` with
-                any other ptypte. Non-allowed ptype connections will emit a
+                any other ptypte. Non-allowed ptype connections will log a
                 warning. Order is ignored, i.e. `(a, b)` is equivalent to
                 `(b, a)`.
 
@@ -520,11 +518,11 @@ class PortList(metaclass=ABCMeta):
                                       for st, ot in zip(s_types, o_types, strict=True)])
         if type_conflicts.any():
             msg = 'Ports have conflicting types:\n'
-            for nn, (k, v) in enumerate(map_in.items()):
+            for nn, (kk, vv) in enumerate(map_in.items()):
                 if type_conflicts[nn]:
-                    msg += f'{k} | {s_types[nn]}:{o_types[nn]} | {v}\n'
-            msg = ''.join(traceback.format_stack()) + '\n' + msg
-            warnings.warn(msg, stacklevel=2)
+                    msg += f'{kk} | {s_types[nn]}:{o_types[nn]} | {vv}\n'
+            msg += '\nStack trace:\n' + format_stacktrace()
+            logger.warning(msg)
 
         rotations = numpy.mod(s_rotations - o_rotations - pi, 2 * pi)
         if not has_rot.any():
@@ -546,8 +544,11 @@ class PortList(metaclass=ABCMeta):
         translations = s_offsets - o_offsets
         if not numpy.allclose(translations[:1], translations):
             msg = 'Port translations do not match:\n'
+            common_translation = numpy.min(translations, axis=0)
+            msg += f'Common: {common_translation} \n'
+            msg += 'Deltas:\n'
             for nn, (kk, vv) in enumerate(map_in.items()):
-                msg += f'{kk} | {translations[nn]} | {vv}\n'
+                msg += f'{kk} | {translations[nn] - common_translation} | {vv}\n'
             raise PortError(msg)
 
         return translations[0], rotations[0], o_offsets[0]
diff --git a/masque/traits/positionable.py b/masque/traits/positionable.py
index fd8551b..6779869 100644
--- a/masque/traits/positionable.py
+++ b/masque/traits/positionable.py
@@ -1,4 +1,4 @@
-from typing import Self, Any
+from typing import Self
 from abc import ABCMeta, abstractmethod
 
 import numpy