diff --git a/CMakeLists.txt b/CMakeLists.txt
index e41e9a9..2b11d93 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -113,13 +113,18 @@ if(APPLE)
   # See: https://github.com/openMVG/openMVG/issues/1349#issuecomment-401492811
   set(CMAKE_FIND_FRAMEWORK LAST)
 
-  # use brewed llvm's libc++
-  # Note: the suffix "/../v1" for the include path is needed to work around a recent cmake issue:
-  # https://gitlab.kitware.com/cmake/cmake/issues/19251#note_571030
-  include_directories("/usr/local/opt/llvm/include/c++/v1/../v1")
-  link_directories("/usr/local/opt/llvm/lib")
-  add_compile_options("-nostdinc++")
-  set(STD_CXX_FS c++fs)
+  if(CMAKE_SYSTEM_VERSION VERSION_LESS 19.0.0)
+      # use brewed llvm's libc++
+      # Note: the suffix "/../v1" for the include path is needed to work around a recent cmake issue:
+      # https://gitlab.kitware.com/cmake/cmake/issues/19251#note_571030
+      include_directories("/usr/local/opt/llvm/include/c++/v1/../v1")
+      link_directories("/usr/local/opt/llvm/lib")
+      add_compile_options("-nostdinc++")
+      set(STD_CXX_FS c++fs)
+  endif()
+
+
+
 
   if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
     message(STATUS "Detected macOS with non-Apple clang")
diff --git a/include/basalt/optimization/accumulator.h b/include/basalt/optimization/accumulator.h
index 56b23b4..420cc66 100644
--- a/include/basalt/optimization/accumulator.h
+++ b/include/basalt/optimization/accumulator.h
@@ -33,8 +33,7 @@ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
-#ifndef BASALT_ACCUMULATOR_H
-#define BASALT_ACCUMULATOR_H
+#pragma once
 
 #include <Eigen/Dense>
 #include <Eigen/Sparse>
@@ -45,6 +44,20 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <basalt/utils/assert.h>
 
+#if defined(BASALT_USE_CHOLMOD)
+
+#include <Eigen/CholmodSupport>
+
+template <class T>
+using SparseLLT = Eigen::CholmodSupernodalLLT<T>;
+
+#else
+
+template <class T>
+using SparseLLT = Eigen::SimplicialLDLT<T>;
+
+#endif
+
 namespace basalt {
 
 template <typename Scalar = double>
@@ -195,7 +208,7 @@ class SparseHashAccumulator {
       cg.compute(sm);
       res = cg.solve(b);
     } else {
-      Eigen::SimplicialLDLT<SparseMatrix> chol(sm);
+      SparseLLT<SparseMatrix> chol(sm);
       res = chol.solve(b);
     }
 
@@ -261,5 +274,3 @@ class SparseHashAccumulator {
 };
 
 }  // namespace basalt
-
-#endif
diff --git a/include/basalt/optimization/spline_optimize.h b/include/basalt/optimization/spline_optimize.h
index 36c648c..53a62e3 100644
--- a/include/basalt/optimization/spline_optimize.h
+++ b/include/basalt/optimization/spline_optimize.h
@@ -87,10 +87,10 @@ class SplineOptimization {
 
   typedef Se3Spline<N, Scalar> SplineT;
 
-  SplineOptimization(int64_t dt_ns = 1e7)
+  SplineOptimization(int64_t dt_ns = 1e7, double init_lambda = 1e-12)
       : pose_var(1e-4),
         mocap_initialized(false),
-        lambda(1e-12),
+        lambda(init_lambda),
         min_lambda(1e-18),
         max_lambda(100),
         lambda_vee(2),
@@ -367,7 +367,8 @@ class SplineOptimization {
   bool optimize(bool use_intr, bool use_poses, bool use_april_corners,
                 bool opt_cam_time_offset, bool opt_imu_scale, bool use_mocap,
                 double huber_thresh, double stop_thresh, double& error,
-                int& num_points, double& reprojection_error) {
+                int& num_points, double& reprojection_error,
+                bool print_info = true) {
     // std::cerr << "optimize num_knots " << num_knots << std::endl;
 
     ccd.opt_intrinsics = use_intr;
@@ -419,8 +420,9 @@ class SplineOptimization {
     num_points = lopt.num_points;
     reprojection_error = lopt.reprojection_error;
 
-    std::cout << "[LINEARIZE] Error: " << lopt.error << " num points "
-              << lopt.num_points << std::endl;
+    if (print_info)
+      std::cout << "[LINEARIZE] Error: " << lopt.error << " num points "
+                << lopt.num_points << std::endl;
 
     lopt.accum.setup_solver();
     Eigen::VectorXd Hdiag = lopt.accum.Hdiagonal();
@@ -473,10 +475,11 @@ class SplineOptimization {
       double step_quality = f_diff / l_diff;
 
       if (step_quality < 0) {
-        std::cout << "\t[REJECTED] lambda:" << lambda
-                  << " step_quality: " << step_quality
-                  << " max_inc: " << max_inc << " Error: " << eopt.error
-                  << " num points " << eopt.num_points << std::endl;
+        if (print_info)
+          std::cout << "\t[REJECTED] lambda:" << lambda
+                    << " step_quality: " << step_quality
+                    << " max_inc: " << max_inc << " Error: " << eopt.error
+                    << " num points " << eopt.num_points << std::endl;
         lambda = std::min(max_lambda, lambda_vee * lambda);
         lambda_vee *= 2;
 
@@ -486,10 +489,11 @@ class SplineOptimization {
         g = g_backup;
 
       } else {
-        std::cout << "\t[ACCEPTED] lambda:" << lambda
-                  << " step_quality: " << step_quality
-                  << " max_inc: " << max_inc << " Error: " << eopt.error
-                  << " num points " << eopt.num_points << std::endl;
+        if (print_info)
+          std::cout << "\t[ACCEPTED] lambda:" << lambda
+                    << " step_quality: " << step_quality
+                    << " max_inc: " << max_inc << " Error: " << eopt.error
+                    << " num points " << eopt.num_points << std::endl;
 
         lambda = std::max(
             min_lambda,
@@ -506,7 +510,7 @@ class SplineOptimization {
       max_iter--;
     }
 
-    if (converged) {
+    if (converged && print_info) {
       std::cout << "[CONVERGED]" << std::endl;
     }