diff --git a/device/common/include/traccc/device/array_insertion_mutex.hpp b/device/common/include/traccc/device/array_insertion_mutex.hpp
new file mode 100644
index 0000000000..6e2b6e5d4a
--- /dev/null
+++ b/device/common/include/traccc/device/array_insertion_mutex.hpp
@@ -0,0 +1,42 @@
+/** TRACCC library, part of the ACTS project (R&D line)
+ *
+ * (c) 2025 CERN for the benefit of the ACTS project
+ *
+ * Mozilla Public License Version 2.0
+ */
+
+#pragma once
+
+#include <cstdint>
+#include <tuple>
+
+#include "traccc/definitions/qualifiers.hpp"
+
+namespace traccc::device {
+/**
+ * @brief Encode the state of our parameter insertion mutex.
+ */
+TRACCC_HOST_DEVICE inline uint64_t encode_insertion_mutex(const bool locked,
+                                                          const uint32_t size,
+                                                          const float max) {
+    // Assert that the MSB of the size is zero
+    assert(size <= 0x7FFFFFFF);
+
+    const uint32_t hi = size | (locked ? 0x80000000 : 0x0);
+    const uint32_t lo = std::bit_cast<uint32_t>(max);
+
+    return (static_cast<uint64_t>(hi) << 32) | lo;
+}
+
+/**
+ * @brief Decode the state of our parameter insertion mutex.
+ */
+TRACCC_HOST_DEVICE inline std::tuple<bool, uint32_t, float>
+decode_insertion_mutex(const uint64_t val) {
+    const uint32_t hi = static_cast<uint32_t>(val >> 32);
+    const uint32_t lo = val & 0xFFFFFFFF;
+
+    return {static_cast<bool>(hi & 0x80000000), (hi & 0x7FFFFFFF),
+            std::bit_cast<float>(lo)};
+}
+}  // namespace traccc::device
diff --git a/device/common/include/traccc/finding/device/impl/find_tracks.ipp b/device/common/include/traccc/finding/device/impl/find_tracks.ipp
index 801ecd8527..ab21f177b8 100644
--- a/device/common/include/traccc/finding/device/impl/find_tracks.ipp
+++ b/device/common/include/traccc/finding/device/impl/find_tracks.ipp
@@ -21,6 +21,7 @@
 #endif
 
 // Project include(s).
+#include "traccc/device/array_insertion_mutex.hpp"
 #include "traccc/fitting/kalman_filter/gain_matrix_updater.hpp"
 #include "traccc/fitting/kalman_filter/is_line_visitor.hpp"
 #include "traccc/fitting/status_codes.hpp"
@@ -34,35 +35,6 @@
 
 namespace traccc::device {
 
-namespace details {
-/**
- * @brief Encode the state of our parameter insertion mutex.
- */
-TRACCC_HOST_DEVICE inline uint64_t encode_insertion_mutex(const bool locked,
-                                                          const uint32_t size,
-                                                          const float max) {
-    // Assert that the MSB of the size is zero
-    assert(size <= 0x7FFFFFFF);
-
-    const uint32_t hi = size | (locked ? 0x80000000 : 0x0);
-    const uint32_t lo = std::bit_cast<uint32_t>(max);
-
-    return (static_cast<uint64_t>(hi) << 32) | lo;
-}
-
-/**
- * @brief Decode the state of our parameter insertion mutex.
- */
-TRACCC_HOST_DEVICE inline std::tuple<bool, uint32_t, float>
-decode_insertion_mutex(const uint64_t val) {
-    const uint32_t hi = static_cast<uint32_t>(val >> 32);
-    const uint32_t lo = val & 0xFFFFFFFF;
-
-    return {static_cast<bool>(hi & 0x80000000), (hi & 0x7FFFFFFF),
-            std::bit_cast<float>(lo)};
-}
-}  // namespace details
-
 template <typename detector_t, concepts::thread_id1 thread_id_t,
           concepts::barrier barrier_t>
 TRACCC_HOST_DEVICE inline void find_tracks(
@@ -108,7 +80,7 @@ TRACCC_HOST_DEVICE inline void find_tracks(
     }
 
     shared_payload.shared_insertion_mutex[thread_id.getLocalThreadIdX()] =
-        details::encode_insertion_mutex(false, 0, 0.f);
+        encode_insertion_mutex(false, 0, 0.f);
 
     barrier.blockBarrier();
 
@@ -339,8 +311,7 @@ TRACCC_HOST_DEVICE inline void find_tracks(
                  *         currently operating on the array guarded.
                  */
                 unsigned long long int assumed = *mutex_ptr;
-                auto [locked, size, max] =
-                    details::decode_insertion_mutex(assumed);
+                auto [locked, size, max] = decode_insertion_mutex(assumed);
 
                 /*
                  * If the array is already full _and_ our parameter has a
@@ -357,7 +328,7 @@ TRACCC_HOST_DEVICE inline void find_tracks(
                  * locked.
                  */
                 if (result.has_value() && !locked) {
-                    desired = details::encode_insertion_mutex(true, size, max);
+                    desired = encode_insertion_mutex(true, size, max);
 
                     /*
                      * Attempt to CAS the mutex with the same value as before
@@ -496,8 +467,8 @@ TRACCC_HOST_DEVICE inline void find_tracks(
                             unsigned long long,
                             vecmem::device_address_space::local>(*mutex_ptr)
                             .compare_exchange_strong(
-                                desired, details::encode_insertion_mutex(
-                                             false, new_size, new_max));
+                                desired, encode_insertion_mutex(false, new_size,
+                                                                new_max));
 
                     assert(cas_result);
                 }
@@ -563,7 +534,7 @@ TRACCC_HOST_DEVICE inline void find_tracks(
      * at which this block will write.
      */
     if (in_param_is_live) {
-        local_num_params = std::get<1>(details::decode_insertion_mutex(
+        local_num_params = std::get<1>(decode_insertion_mutex(
             shared_payload
                 .shared_insertion_mutex[thread_id.getLocalThreadIdX()]));
         /*