diff --git a/src/qrisp/simulator/bi_array_helper.py b/src/qrisp/simulator/bi_array_helper.py
index d02225b4..eacc84a2 100644
--- a/src/qrisp/simulator/bi_array_helper.py
+++ b/src/qrisp/simulator/bi_array_helper.py
@@ -541,7 +541,7 @@ def sparse_matrix_mult(A, B):
         log_sparsity_a = -np.log2(B.nnz/(B.shape[0]*B.shape[1]))
         log_sparsity_b = -np.log2(A.nnz/(A.shape[0]*A.shape[1]))
     
-    if get_prediction(log_shape_0_a, log_shape_1_b, log_sparsity_a, log_sparsity_b):
+    if get_prediction(log_shape_0_a, log_shape_1_b, log_sparsity_a, log_sparsity_b) and False:
         return (A @ B).tocoo()
     else:
         return  coo_sparse_matrix_mult(A, B)
diff --git a/src/qrisp/simulator/bi_arrays.py b/src/qrisp/simulator/bi_arrays.py
index 17459a1a..0c788f45 100644
--- a/src/qrisp/simulator/bi_arrays.py
+++ b/src/qrisp/simulator/bi_arrays.py
@@ -677,43 +677,15 @@ def multi_measure(self, indices, return_new_arrays = True):
                 
         
         return new_bi_arrays, p_list, outcome_index_list
-        
-            
-            
-
-        col_indices = sprs.indices
-        row_ptr = sprs.indptr
-        data = sprs.data
-
-        for r in range(len(row_ptr) - 1):
-            if row_ptr[r] != row_ptr[r + 1]:
-                
-                temp_data = data[row_ptr[r] : row_ptr[r + 1]]
-                p = np.abs(np.vdot(temp_data, temp_data))
-                
-                if p < float_tresh:
-                    continue
-                
-                p_list.append(p)
-                outcome_index_list.append(r)
-                
-                if return_new_arrays:
-                
-                    new_bi_array = SparseBiArray(
-                        (
-                            col_indices[row_ptr[r] : row_ptr[r + 1]].astype(np.int64),
-                            data[row_ptr[r] : row_ptr[r + 1]],
-                        ),
-                        shape=(self.size // 2 ** len(indices),),
-                    )
     
-                    new_bi_arrays.append(new_bi_array)
-                else:
-                    
-                    new_bi_arrays.append(None)
-
-        return new_bi_arrays, p_list, outcome_index_list
-
+    # Should return a cheap guess whether two inputs are linearly independent
+    def exclude_linear_indpendence(self, other):
+        
+        if not 0.5 < len(self.data)/len(other.data) < 2:
+            return False
+        return True
+        
+        
     # Calculate the squared norm, ie. the sesquilinear scalar product of self with
     # itself
     def squared_norm(self):
@@ -1135,6 +1107,10 @@ def vdot(self, other):
         self.apply_swaps()
         other.apply_swaps()
         return np.vdot(self.data, other.data)
+    
+    # Should return a cheap guess whether two inputs are linearly independent
+    def exclude_linear_indpendence(self, other):
+        return True
 
     # This method works similarly as it's equivalent in SparseBiArray
     def to_array(self):
diff --git a/src/qrisp/simulator/circuit_preprocessing.py b/src/qrisp/simulator/circuit_preprocessing.py
index ce5bd21b..d272add3 100644
--- a/src/qrisp/simulator/circuit_preprocessing.py
+++ b/src/qrisp/simulator/circuit_preprocessing.py
@@ -846,13 +846,8 @@ def circuit_preprocessor(qc):
         return qc.copy()
 
     # TO-DO find reliable classifiaction when automatic disentangling works best
-    if len(qc.qubits) < 26:
-        qc = group_qc(qc)
-    elif len(qc.qubits) < 34:
-        qc = group_qc(qc)
+    if len(qc.qubits) > 45:
         qc = insert_disentangling(qc)
-    else:
-        qc = insert_disentangling(qc)
-        qc = group_qc(qc)
+    qc = group_qc(qc)
     
     return reorder_circuit(qc, ["measure", "reset", "disentangle"])
diff --git a/src/qrisp/simulator/tensor_factor.py b/src/qrisp/simulator/tensor_factor.py
index ae196ec2..9110431b 100644
--- a/src/qrisp/simulator/tensor_factor.py
+++ b/src/qrisp/simulator/tensor_factor.py
@@ -228,6 +228,9 @@ def disentangle(self, qubit):
             # print("disentangling successfull")
             return TensorFactor([qubit], temp), TensorFactor(new_qubits, new_bi_arrays[0])
         
+        if not new_bi_arrays[0].exclude_linear_indpendence(new_bi_arrays[1]):
+            return self, self
+        
         vdot_value = new_bi_arrays[0].vdot(new_bi_arrays[1])