diff --git a/src/libslic3r/Support/TreeSupport.cpp b/src/libslic3r/Support/TreeSupport.cpp
index 5aeb7f65c..912338735 100644
--- a/src/libslic3r/Support/TreeSupport.cpp
+++ b/src/libslic3r/Support/TreeSupport.cpp
@@ -890,7 +890,7 @@ void TreeSupport::detect_overhangs(bool check_support_necessity/* = false*/)
                 if (layer->lower_layer == nullptr) {
                     for (auto& slice : layer->lslices_extrudable) {
                         auto bbox_size = get_extents(slice).size();
-                        if (!((bbox_size.x() > length_thresh_well_supported && bbox_size.y() > length_thresh_well_supported))
+                        if (!((bbox_size.x() > length_thresh_well_supported || bbox_size.y() > length_thresh_well_supported))
                             && g_config_support_sharp_tails) {
                             layer->sharp_tails.push_back(slice);
                             layer->sharp_tails_height.push_back(layer->height);
@@ -2299,12 +2299,13 @@ void TreeSupport::draw_circles()
 
                         // merge overhang to get a smoother interface surface
                         // Do not merge when buildplate_only is on, because some underneath nodes may have been deleted.
-                        if (top_interface_layers > 0 && node.support_roof_layers_below >=0 && !on_buildplate_only) {
+                        if (top_interface_layers > 0 && (node.support_roof_layers_below > 1 || (node.support_roof_layers_below >= 0 && !node.is_sharp_tail)) &&
+                            !on_buildplate_only) {
                             ExPolygons overhang_expanded;
-                            if (node.overhang.contour.size() > 100 || node.overhang.holes.size()>1)
+                            if (node.overhang.contour.size() > 100 || node.overhang.holes.size() > 1)
                                 overhang_expanded.emplace_back(node.overhang);
                             else {
-                                overhang_expanded = offset_ex({ node.overhang }, scale_(m_ts_data->m_xy_distance));
+                                overhang_expanded = offset_ex({node.overhang}, scale_(m_ts_data->m_xy_distance));
                             }
                             append(area, overhang_expanded);
                         }
@@ -2345,6 +2346,10 @@ void TreeSupport::draw_circles()
                 roof_1st_layer = intersection_ex(roof_1st_layer, m_machine_border);
 
                 ExPolygons roofs; append(roofs, roof_1st_layer); append(roofs, roof_areas);append(roofs, roof_gap_areas);
+
+                // slightly slow down the slicing speed
+                base_areas = diff_ex(base_areas, collision_base.empty() ? m_ts_data->get_collision(0, obj_layer_nr) : collision_base);
+
                 base_areas = diff_ex(base_areas, ClipperUtils::clip_clipper_polygons_with_subject_bbox(roofs, get_extents(base_areas)));
                 base_areas = intersection_ex(base_areas, m_machine_border);
 
@@ -3774,9 +3779,9 @@ void TreeSupport::generate_contact_points()
                 if (add_interface && xy_expansion > EPSILON && !is_sharp_tail) {
                     overhangs = safe_offset_inc(overhangs, xy_expansion, relevant_forbidden, scale_(MIN_BRANCH_RADIUS * 1.75), 0, 1);
                 }
-                overhangs_no_extra_expand = (unscale_(xy_expansion) - config.support_expansion.value) > EPSILON ?
-                                            safe_offset_inc({overhang_part}, scale_(config.support_expansion.value), relevant_forbidden, scale_(MIN_BRANCH_RADIUS * 1.75), 0, 1) :
-                                            overhangs;
+                overhangs_no_extra_expand = (!is_sharp_tail && (unscale_(xy_expansion) - config.support_expansion.value > EPSILON) && (config.support_expansion.value > EPSILON)) ?
+                                                safe_offset_inc({overhang_part}, scale_(config.support_expansion.value), relevant_forbidden, scale_(MIN_BRANCH_RADIUS * 1.75), 0, 1) :
+                                                overhangs;
                 if (m_support_params.support_style == smsTreeHybrid &&
                     (overhang_type & (BigFlat | ThinPlate))) {
                     overhangs_regular           = offset_ex(intersection_ex(overhangs, m_ts_data->m_layer_outlines_below[layer_nr - 1]), radius_scaled);
@@ -3812,6 +3817,7 @@ void TreeSupport::generate_contact_points()
                 }
 
                 for (auto &overhang : overhangs_regular) {
+                    if (is_sharp_tail && overhang.area() < SQ(scale_(2.))) add_interface = false;
                     BoundingBox overhang_bounds = get_extents(overhang);
                     double      radius          = std::clamp(unscale_(overhang_bounds.radius()), MIN_BRANCH_RADIUS, base_radius);
                     // add supports at corners for both auto and manual overhangs, github #2008