diff --git a/release.md b/release.md
index cfa6a7e7..1d68e3bb 100644
--- a/release.md
+++ b/release.md
@@ -9,6 +9,7 @@ Full docs @ https://docs.grid.space/projects/kiri-moto
 ## Kiri:moto
 
 * `C` added batch processing to object adds/removes to speedup complex workspace restore
+* `C` substitute some prusa slicer [variables] with KM {variables} on import
 * `C` fix CAM output order for tool changes an spindle speed updates
 * `I` add CAM pocket operation using surface selection
 * `-` refactor cnc to use new core slicer engine
@@ -16,6 +17,7 @@ Full docs @ https://docs.grid.space/projects/kiri-moto
 
 ## Mesh:Tool
 
+* `C` significant speed-up for large surface selections
 * `C` multi-body identification and isolation
 * `-` parameterize svg and image import
 
diff --git a/src/kiri/settings.js b/src/kiri/settings.js
index 331ad950..d5165ce1 100644
--- a/src/kiri/settings.js
+++ b/src/kiri/settings.js
@@ -618,6 +618,11 @@ function settingsImportZip(data, ask) {
 function settingsPrusaConvert(data) {
     const { uc } = api;
     const map = {};
+    const vsub = {
+        '[first_layer_bed_temperature]': '{bed_temp}',
+        '[first_layer_temperature]': '{temp}',
+        '[layer_z]': '{z}'
+    };
     try {
         data.split('\n')
             .filter(l => l.charAt(0) !== '#')
@@ -625,7 +630,13 @@ function settingsPrusaConvert(data) {
             .map(l => {
                 // convert gcode string into a string array
                 if (l[0].indexOf('_gcode') > 0) {
-                    l[1] = l[1].replaceAll('\\n','\n').split('\n');
+                    l[1] = l[1].replaceAll('\\n','\n').split('\n')
+                        .map(line => {
+                            for (let [k,v] of Object.entries(vsub)) {
+                                line = line.replace(k,v);
+                            }
+                            return line;
+                        });
                 }
                 return l;
             })
diff --git a/src/mesh/api.js b/src/mesh/api.js
index 428a4170..b38aa588 100644
--- a/src/mesh/api.js
+++ b/src/mesh/api.js
@@ -424,7 +424,7 @@ const tool = {
         models = fallback(models);
         api.log.emit('mapping faces').pin();
         let promises = [];
-        // let mark = Date.now();
+        let mark = Date.now();
         for (let m of models) {
             let p = worker.model_mapFaces({ id: m.id, opt }).then(data => {
                 // console.log({map_info: data});
@@ -433,7 +433,7 @@ const tool = {
         }
         Promise.all(promises).then(() => {
             api.log.emit('mapping complete').unpin();
-            // api.log.emit(`... time = ${Date.now() - mark}`);
+            api.log.emit(`... map time = ${Date.now() - mark}`);
         });
     },
 
diff --git a/src/mesh/model.js b/src/mesh/model.js
index 5cb8cd31..33c68024 100644
--- a/src/mesh/model.js
+++ b/src/mesh/model.js
@@ -529,14 +529,32 @@ mesh.model = class MeshModel extends mesh.object {
 
     selectFaces(list = [], action = {}) {
         let faces = this.sel.faces;
-        for (let t of list) {
-            if (action.toggle) {
-                faces.remove(t) || faces.addOnce(t);
-            } else if (action.clear) {
-                faces.remove(t);
-            } else if (action.select) {
-                faces.addOnce(t);
+        let map = {};
+        for (let f of list) {
+            map[f] = f;
+        }
+        if (action.toggle) {
+            faces = faces.filter(f => {
+                if (map[f] !== undefined) {
+                    map[f] = undefined;
+                    return false;
+                } else {
+                    return true;
+                }
+            });
+            faces.appendAll(Object.entries(map).filter(kv => {
+                return kv[1] !== undefined;
+            }).map(kv => {
+                return kv[1];
+            }));
+            this.sel.faces = faces;
+        } else if (action.clear) {
+            this.sel.faces = faces.filter(f => map[f] === undefined);
+        } else if (action.select) {
+            for (let f of faces) {
+                map[f] = undefined;
             }
+            faces.appendAll(Object.values(map).filter(f => f !== undefined));
         }
     }
 
@@ -576,9 +594,11 @@ mesh.model = class MeshModel extends mesh.object {
             timer = undefined;
             mesh.api.log.emit("matching surface").pin();
         }, 150);
+        // let mark = Date.now();
         worker.model_select({
             id: this.id, x, y:-z, z:y, a, b, c, matrix: this.matrix, surface
         }).then(data => {
+            // mesh.api.log.emit(`... data time = ${Date.now() - mark}`); mark = Date.now();
             if (timer) {
                 clearTimeout(timer);
             }
@@ -586,11 +606,13 @@ mesh.model = class MeshModel extends mesh.object {
             // console.log({data});
             // this.toggleSelectedVertices(verts);
             this.selectFaces(faces, action);
+            // mesh.api.log.emit(`... select time = ${Date.now() - mark}`); mark = Date.now();
             this.updateSelections();
             if (!timer) {
                 mesh.api.log.emit("surface match complete").unpin();
                 moto.space.refresh();
             }
+            // mesh.api.log.emit(`... paint time = ${Date.now() - mark}`);
         });
     }
 
diff --git a/src/mesh/tool.js b/src/mesh/tool.js
index c846cd6e..ff9fbc77 100644
--- a/src/mesh/tool.js
+++ b/src/mesh/tool.js
@@ -200,7 +200,7 @@ mesh.tool = class MeshTool {
                 const s2 = (v2 < v0 ? v2 + "," + v0 : v0 + ","  +v2);
                 // for storing raw vertex offset in side record
                 const [ vr0, vr1, vr2 ] = viraw;
-                const vv = [ vr0, vr1, vr1, vr2, vr2, vr0 ];
+                // const vv = [ vr0, vr1, vr1, vr2, vr2, vr0 ];
                 // store face indexes into sdrec array for each side
                 const smap = [ s0, s1, s2 ].map((key,ki) => {
                     let sid = simap[key], sdoff, sdcnt;
@@ -208,8 +208,10 @@ mesh.tool = class MeshTool {
                         sid = simap[key] = sn++;
                         sdcnt = srecs[sid] = 1;
                         sdoff = sid * 4;
-                        sides[sdoff] = vv[ki * 2];
-                        sides[sdoff + 1] = vv[ki * 2 + 1];
+                        // sides[sdoff] = vv[ki * 2];
+                        // sides[sdoff + 1] = vv[ki * 2 + 1];
+                        sides[sdoff] = viraw[ki];
+                        sides[sdoff + 1] = viraw[(ki + 1) % 3];
                     } else {
                         sdoff = sid * 4;
                         sdcnt = ++srecs[sid];
@@ -236,7 +238,7 @@ mesh.tool = class MeshTool {
         this.indexed = {
             faces, sides, sideExt
         };
-        // console.log(this.indexed);
+        console.log(this.indexed);
     }
 
     getAdjacentFaces(face) {