diff --git a/src/kiri/conf.js b/src/kiri/conf.js
index 7ce8531d..12eb7115 100644
--- a/src/kiri/conf.js
+++ b/src/kiri/conf.js
@@ -296,6 +296,7 @@
                     sliceSupportExtra: 0,
                     sliceSupportAngle: 50,
                     sliceSupportNozzle: 0,
+                    sliceSupportEnable: false,
                     sliceSolidMinArea: 1,
                     sliceSolidLayers: 3,
                     sliceBottomLayers: 3,
diff --git a/src/kiri/init.js b/src/kiri/init.js
index 7dcbf233..a5a6b70a 100644
--- a/src/kiri/init.js
+++ b/src/kiri/init.js
@@ -1655,6 +1655,7 @@
             sliceSupportExtra:   UC.newInput(LANG.sp_xpnd_s, {title:LANG.sp_xpnd_l, bound:UC.bound(0.0,200.0), convert:UC.toFloat, modes:FDM}),
             fdmSep:              UC.newBlank({class:"pop-sep", modes:FDM}),
             sliceSupportAngle:   UC.newInput(LANG.sp_angl_s, {title:LANG.sp_angl_l, bound:UC.bound(0.0,90.0), convert:UC.toFloat, modes:FDM}),
+            sliceSupportEnable:  UC.newBoolean(LANG.sp_auto_s, onBooleanClick, {title:LANG.sp_auto_l, modes:FDM, show:isNotBelt}),
 
             sliceSupportGen:     UC.newRow([
                 UI.ssaGen = UC.newButton(LANG.sp_detect, onButtonClick, {class: "f-col grow a-center"})
diff --git a/src/mode/fdm/slice.js b/src/mode/fdm/slice.js
index ba80488e..c248115a 100644
--- a/src/mode/fdm/slice.js
+++ b/src/mode/fdm/slice.js
@@ -199,8 +199,8 @@
 
             // fixed supports (generated ahead of time)
             const fixed = Object.values(settings.widget[widget.id].support || {});
-            let shadow;
-            if (fixed.length) {
+            let shadow = null;
+            if (fixed.length || spro.sliceSupportEnable) {
                 // create shadow. TODO test if any supports set
                 let alltops = slices.map(slice => slice.topPolys()).flat();
                 shadow = POLY.union(alltops,null,0.1);
@@ -946,7 +946,7 @@
             });
 
             // merge pillars and replace with convex hull of outer points (aka smoothing)
-            pillars = POLY.union(pillars).forEach(function(pillar) {
+            pillars = POLY.union(pillars, null, true).forEach(function(pillar) {
                 supports.push(BASE.newPolygon().createConvexHull(pillar.points));
             });
         })();
diff --git a/web/kiri/lang/en.js b/web/kiri/lang/en.js
index eb39f2e6..dabb4f76 100644
--- a/web/kiri/lang/en.js
+++ b/web/kiri/lang/en.js
@@ -251,8 +251,8 @@ kiri.lang['en-us'] = {
     sp_xpnd_l:      "expand support area\nbeyond part boundary\nin millimeters",
     sp_nozl_s:      "extruder",
     sp_nozl_l:      "in multi-extruder systems\nthe extruder to use for\nsupport material",
-    sp_auto_s:      "enable auto",
-    sp_auto_l:      "enable generated supports\nusing specified parameters",
+    sp_auto_s:      "automatic",
+    sp_auto_l:      "enable generated supports\nusing at-slice-time geometry\nsupports will only appear\nafter slicing completes",
 
     // LASER SLICING
     ls_offs_s:      "offset",