diff --git a/src/libslic3r/SLA/SLABasePool.cpp b/src/libslic3r/SLA/SLABasePool.cpp
index f1e79357d..a235d52ba 100644
--- a/src/libslic3r/SLA/SLABasePool.cpp
+++ b/src/libslic3r/SLA/SLABasePool.cpp
@@ -427,6 +427,7 @@ ExPolygons concave_hull(const ExPolygons& polys, double max_dist_mm = 50,
         return r;
     });
 
+    // This is unavoidable...
     punion = unify(punion);
 
     return punion;
@@ -448,10 +449,17 @@ void base_plate(const TriangleMesh &mesh, ExPolygons &output, float h,
     slicer.slice(heights, &out, thrfn);
 
     size_t count = 0; for(auto& o : out) count += o.size();
+
+    // Now we have to unify all slice layers which can be an expensive operation
+    // so we will try to simplify the polygons
     ExPolygons tmp; tmp.reserve(count);
-    for(auto& o : out) for(auto& e : o) tmp.emplace_back(std::move(e));
+    for(ExPolygons& o : out) for(ExPolygon& e : o) {
+        auto&& exss = e.simplify(0.1/SCALING_FACTOR);
+        for(ExPolygon& ep : exss) tmp.emplace_back(std::move(ep));
+    }
 
     ExPolygons utmp = unify(tmp);
+
     for(auto& o : utmp) {
         auto&& smp = o.simplify(0.1/SCALING_FACTOR);
         output.insert(output.end(), smp.begin(), smp.end());
diff --git a/src/libslic3r/SLAPrint.cpp b/src/libslic3r/SLAPrint.cpp
index 7da47fae7..142428f1d 100644
--- a/src/libslic3r/SLAPrint.cpp
+++ b/src/libslic3r/SLAPrint.cpp
@@ -363,7 +363,11 @@ SLAPrint::ApplyStatus SLAPrint::apply(const Model &model, const DynamicPrintConf
             const_cast<PrintObjectStatus&>(*it_print_object_status).status = PrintObjectStatus::Reused;
         } else {
             auto print_object = new SLAPrintObject(this, &model_object);
+
+            // FIXME: this invalidates the transformed mesh in SLAPrintObject
+            // which is expensive to calculate (especially the raw_mesh() call)
             print_object->set_trafo(sla_trafo(model_object));
+
             print_object->set_instances(new_instances);
             print_object->config_apply(config, true);
             print_objects_new.emplace_back(print_object);
@@ -621,8 +625,8 @@ void SLAPrint::process()
         // repeated)
 
         if(!po.m_supportdata || !po.m_supportdata->support_tree_ptr) {
-            BOOST_LOG_TRIVIAL(warning) << "Uninitialized support data at "
-                                       << "pad creation.";
+            BOOST_LOG_TRIVIAL(error) << "Uninitialized support data at "
+                                     << "pad creation.";
             return;
         }
 
@@ -644,9 +648,11 @@ void SLAPrint::process()
             // This call can get pretty time consuming
             auto thrfn = [this](){ throw_if_canceled(); };
 
-            if(elevation < pad_h)
+            if(elevation < pad_h) {
+                // we have to count with the model geometry for the base plate
                 sla::base_plate(trmesh, bp, float(pad_h), float(lh),
                                             thrfn);
+            }
 
             pcfg.throw_on_cancel = thrfn;
             po.m_supportdata->support_tree_ptr->add_pad(bp, pcfg);
@@ -940,7 +946,7 @@ void SLAPrint::process()
     };
 
     // this would disable the rasterization step
-//    m_stepmask[slapsRasterize] = false;
+    // m_stepmask[slapsRasterize] = false;
 
     double pstd = (100 - max_objstatus) / 100.0;
     st = max_objstatus;