diff --git a/lib/commands.py b/lib/commands.py
index 8e35d7ee0..c735185f6 100644
--- a/lib/commands.py
+++ b/lib/commands.py
@@ -289,6 +289,10 @@ def add_connector(document, symbol, element):
     start_pos = (symbol.get('x'), symbol.get('y'))
     end_pos = element.shape.centroid
 
+    # Make sure the element's XML node has an id so that we can reference it.
+    if element.node.get('id') is None:
+        element.node.set('id', generate_unique_id(document, "object"))
+
     path = inkex.etree.Element(SVG_PATH_TAG,
                                {
                                    "id": generate_unique_id(document, "connector"),
diff --git a/lib/elements/stroke.py b/lib/elements/stroke.py
index 3ae2b1434..e0a0aaccb 100644
--- a/lib/elements/stroke.py
+++ b/lib/elements/stroke.py
@@ -1,11 +1,13 @@
 import sys
+
 import shapely.geometry
 
-from .element import param, EmbroideryElement, Patch
 from ..i18n import _
-from ..utils import cache, Point
 from ..stitches import running_stitch, bean_stitch
 from ..svg import parse_length_with_units
+from ..utils import cache, Point
+from .element import param, EmbroideryElement, Patch
+
 
 warned_about_legacy_running_stitch = False
 
@@ -85,7 +87,11 @@ class Stroke(EmbroideryElement):
     @cache
     def shape(self):
         line_strings = [shapely.geometry.LineString(path) for path in self.paths]
-        return shapely.geometry.MultiLineString(line_strings)
+
+        # Using convex_hull here is an important optimization.  Otherwise
+        # complex paths cause operations on the shape to take a long time.
+        # This especially happens when importing machine embroidery files.
+        return shapely.geometry.MultiLineString(line_strings).convex_hull
 
     @property
     @param('manual_stitch',
diff --git a/lib/svg/rendering.py b/lib/svg/rendering.py
index 41ed53d7f..532748bf8 100644
--- a/lib/svg/rendering.py
+++ b/lib/svg/rendering.py
@@ -167,9 +167,7 @@ def get_correction_transform(svg):
     return transform
 
 
-def color_block_to_realistic_stitches(color_block, svg):
-    paths = []
-
+def color_block_to_realistic_stitches(color_block, svg, destination):
     for point_list in color_block_to_point_lists(color_block):
         if not point_list:
             continue
@@ -177,7 +175,7 @@ def color_block_to_realistic_stitches(color_block, svg):
         color = color_block.color.visible_on_white.darker.to_hex_str()
         start = point_list[0]
         for point in point_list[1:]:
-            paths.append(inkex.etree.Element(
+            destination.append(inkex.etree.Element(
                 SVG_PATH_TAG,
                 {'style': simplestyle.formatStyle(
                     {
@@ -190,16 +188,23 @@ def color_block_to_realistic_stitches(color_block, svg):
                  }))
             start = point
 
-    return paths
 
-
-def color_block_to_paths(color_block, svg):
-    paths = []
+def color_block_to_paths(color_block, svg, destination):
     # We could emit just a single path with one subpath per point list, but
     # emitting multiple paths makes it easier for the user to manipulate them.
+    first = True
     for point_list in color_block_to_point_lists(color_block):
+        if first:
+            first = False
+        else:
+            # If we try to import these above, we get into a mess of circular
+            # imports.
+            from ..commands import add_commands
+            from ..elements.stroke import Stroke
+            add_commands(Stroke(destination[-1]), ["trim"])
+
         color = color_block.color.visible_on_white.to_hex_str()
-        paths.append(inkex.etree.Element(
+        destination.append(inkex.etree.Element(
             SVG_PATH_TAG,
             {'style': simplestyle.formatStyle(
                 {'stroke': color,
@@ -207,16 +212,9 @@ def color_block_to_paths(color_block, svg):
                  'fill': 'none'}),
              'd': "M" + " ".join(" ".join(str(coord) for coord in point) for point in point_list),
              'transform': get_correction_transform(svg),
-             'embroider_manual_stitch': 'true',
-             'embroider_trim_after': 'true',
+             'embroider_manual_stitch': 'true'
              }))
 
-    # no need to trim at the end of a thread color
-    if paths:
-        paths[-1].attrib.pop('embroider_trim_after')
-
-    return paths
-
 
 def render_stitch_plan(svg, stitch_plan, realistic=False):
     layer = svg.find(".//*[@id='__inkstitch_stitch_plan__']")
@@ -232,17 +230,17 @@ def render_stitch_plan(svg, stitch_plan, realistic=False):
         # make sure the layer is visible
         layer.set('style', 'display:inline')
 
+    svg.append(layer)
+
     for i, color_block in enumerate(stitch_plan):
         group = inkex.etree.SubElement(layer,
                                        SVG_GROUP_TAG,
                                        {'id': '__color_block_%d__' % i,
                                         INKSCAPE_LABEL: "color block %d" % (i + 1)})
         if realistic:
-            group.extend(color_block_to_realistic_stitches(color_block, svg))
+            color_block_to_realistic_stitches(color_block, svg, group)
         else:
-            group.extend(color_block_to_paths(color_block, svg))
-
-    svg.append(layer)
+            color_block_to_paths(color_block, svg, group)
 
     if realistic:
         defs = svg.find(SVG_DEFS_TAG)