diff --git a/projects/Core/CMakeLists.txt b/projects/Core/CMakeLists.txt
index f18f64ceb4f..84cb64e0c22 100644
--- a/projects/Core/CMakeLists.txt
+++ b/projects/Core/CMakeLists.txt
@@ -34,8 +34,9 @@ set(
         "api/messages/text_style.cpp"
         "api/moon_animator_events.cpp"
         "api/scenes/create_objects.cpp"
-        "api/scenes/scene_load.cpp"
         "api/scenes/polygon.cpp"
+        "api/scenes/scene_load.cpp"
+        "api/system/save_files.cpp"
         "api/audio.cpp"
         "api/screen_position.cpp"
         "api/uber_states/uber_state.cpp"
@@ -106,6 +107,7 @@ set(
         "api/scenes/scene_load.h"
         "api/scenes/polygon.h"
         "api/system/message_provider.h"
+        "api/system/save_files.h"
         "api/audio.h"
         "api/screen_position.h"
         "api/uber_states/uber_state.h"
diff --git a/projects/Core/api/system/save_files.cpp b/projects/Core/api/system/save_files.cpp
new file mode 100644
index 00000000000..ec652f23b50
--- /dev/null
+++ b/projects/Core/api/system/save_files.cpp
@@ -0,0 +1,26 @@
+#include <Core/api/game/game.h>
+#include <Core/api/system/save_files.h>
+#include <Core/utils/byte_stream.h>
+#include <Modloader/app/methods/Grdk/Wrapper.h>
+#include <Modloader/app/methods/SaveGameController.h>
+#include <Modloader/app/methods/System/IO/File.h>
+
+using namespace app::classes;
+
+namespace core::api::save_files {
+    app::Byte__Array* get_byte_array(int slot_index, int backup_index) {
+        if (Grdk::Wrapper::get_InitializedOk()) { // Handle GRDK (Xbox Account) saves
+            return Grdk::Wrapper::Load_1(slot_index, backup_index);
+        }
+
+        auto save_info = SaveGameController::GetSaveFileInfo(game::save_controller(), slot_index, backup_index);
+        auto path = save_info->fields.m_FullBackupSaveFilePath;
+        auto path_str = il2cpp::convert_csstring(path);
+        return System::IO::File::ReadAllBytes(path);
+    }
+
+    std::vector<std::byte> get_bytes(int slot_index, int backup_index) {
+        return utils::ByteStream(get_byte_array(slot_index, backup_index)).peek_to_end();
+    }
+}
+
diff --git a/projects/Core/api/system/save_files.h b/projects/Core/api/system/save_files.h
new file mode 100644
index 00000000000..29d633bb691
--- /dev/null
+++ b/projects/Core/api/system/save_files.h
@@ -0,0 +1,21 @@
+#pragma once
+
+#include <vector>
+
+namespace core::api::save_files {
+  /**
+   * Get the on-disk save data for a save file.
+   * @param slot_index Save slot index
+   * @param backup_index Backup slot index. Set this to -1 to request the current game save file.
+   * @return Pointer to an il2cpp array of System.Byte.
+   */
+  CORE_DLLEXPORT app::Byte__Array* get_byte_array(int slot_index, int backup_index = -1);
+
+  /**
+   * Get the on-disk save data for a save file.
+   * @param slot_index Save slot index
+   * @param backup_index Backup slot index.  Set this to -1 to request the current game save file.
+   * @return Byte vector containing the on-disk save data
+   */
+  CORE_DLLEXPORT std::vector<std::byte> get_bytes(int slot_index, int backup_index = -1);
+}
diff --git a/projects/Core/save_meta/save_meta.cpp b/projects/Core/save_meta/save_meta.cpp
index 2d76a999360..96d16bfcabc 100644
--- a/projects/Core/save_meta/save_meta.cpp
+++ b/projects/Core/save_meta/save_meta.cpp
@@ -1,12 +1,13 @@
 #include <Core/api/game/game.h>
+#include <Core/api/system/save_files.h>
 #include <Core/save_meta/save_meta.h>
 #include <Core/utils/byte_stream.h>
 #include <Modloader/app/methods/DeathUberStateManager.h>
+#include <Modloader/app/methods/Grdk/Wrapper.h>
 #include <Modloader/app/methods/Moon/UberStateValueStore.h>
 #include <Modloader/app/methods/SaveGameController.h>
 #include <Modloader/app/methods/SaveSlotsManager.h>
 #include <Modloader/app/methods/System/IO/File.h>
-#include <Modloader/app/methods/Grdk/Wrapper.h>
 #include <Modloader/app/types/Byte.h>
 #include <Modloader/interception_macros.h>
 #include <Modloader/modloader.h>
@@ -268,18 +269,11 @@ namespace core::save_meta {
                 // ...and then load SaveMeta with the ThroughDeathsAndQTMsAndBackups persistence
                 // level from the backup save file if we're on a new/different save slot
                 if (current_save_guid != previous_save_guid) {
-                    app::Byte__Array* bytes;
-
-                    if (Grdk::Wrapper::get_InitializedOk()) {  // Handle GRDK (Xbox Account) saves
-                        bytes = Grdk::Wrapper::Load_1(save_slot_index, backup_slot);
-                    } else {
-                        auto save_info = SaveGameController::GetSaveFileInfo(this_ptr, save_slot_index, backup_slot);
-                        auto path = save_info->fields.m_FullBackupSaveFilePath;
-                        auto path_str = il2cpp::convert_csstring(path);
-                        bytes = System::IO::File::ReadAllBytes(path);
-                    }
-
-                    read_save_meta_from_byte_array(bytes, true, SaveMetaSlotPersistence::ThroughDeathsAndQTMsAndBackups);
+                    read_save_meta_from_byte_array(
+                        api::save_files::get_byte_array(save_slot_index, backup_slot),
+                        true,
+                        SaveMetaSlotPersistence::ThroughDeathsAndQTMsAndBackups
+                    );
                 }
 
                 return return_value;
diff --git a/projects/Randomizer/league/league.cpp b/projects/Randomizer/league/league.cpp
index 6ec0e0bed7b..779c387dbd0 100644
--- a/projects/Randomizer/league/league.cpp
+++ b/projects/Randomizer/league/league.cpp
@@ -31,7 +31,10 @@
 #include <Randomizer/features/credits.h>
 
 #define CPPHTTPLIB_OPENSSL_SUPPORT
+#include <Core/api/system/save_files.h>
 #include <Core/ipc/ipc.h>
+#include <Modloader/app/methods/Grdk/Wrapper.h>
+#include <Modloader/app/methods/System/IO/File.h>
 #include <httplib.h>
 #undef MessageBox
 
@@ -173,7 +176,7 @@ namespace randomizer::league {
             status_message_mutex.unlock();
         }
 
-        void start_submission_thread(const std::string& save_file_path) {
+        void start_submission_thread(const int save_slot_index) {
             using namespace std::chrono_literals;
 
             if (!get_multiverse_id().has_value()) {
@@ -195,11 +198,10 @@ namespace randomizer::league {
             const auto multiverse_id = get_multiverse_id().value();
             const auto jwt = randomizer::online::get_jwt();
 
-            submit_thread = std::make_shared<std::thread>([host, insecure, multiverse_id, jwt, save_file_path]() {
+            submit_thread = std::make_shared<std::thread>([host, insecure, multiverse_id, jwt, save_slot_index]() {
                 upload_attempt.store(0);
 
-                std::ifstream input(save_file_path, std::ios::binary);
-                std::vector<char> save_file_data(std::istreambuf_iterator<char>(input), {});
+                auto save_file_data = core::api::save_files::get_bytes(save_slot_index);
 
                 while (submission_status.load() == SubmissionStatus::Uploading) {
                     const auto attempt = upload_attempt.fetch_add(1) + 1;
@@ -215,7 +217,7 @@ namespace randomizer::league {
                         auto result = client.Post(std::format("/api/league/{}/submission", multiverse_id), {
                             {"User-Agent", std::format("OriAndTheWillOfTheWispsRandomizer/{}", randomizer_version().to_string())},
                             {"Authorization", std::format("Bearer {}", jwt)}
-                        }, save_file_data.data(), save_file_data.size(), "application/octet-stream");
+                        }, reinterpret_cast<char*>(save_file_data.data()), save_file_data.size(), "application/octet-stream");
 
                         if (result.error() != httplib::Error::Success) {
                             set_status_message_thread_safe("Request failed");
@@ -319,8 +321,7 @@ namespace randomizer::league {
                     core::api::audio::play_sound(SoundEventID::LeagueSubmitted);
 
                     const auto save_controller = core::api::game::save_controller();
-                    const auto current_save_file_path = il2cpp::convert_csstring(SaveGameController::get_CurrentSaveFileInfo(save_controller)->fields.m_FullSaveFilePath);
-                    start_submission_thread(current_save_file_path);
+                    start_submission_thread(SaveGameController::get_CurrentSlotIndex(save_controller));
                 });
             } else {
                 const auto resolved_epilogue_timeline = il2cpp::invoke<app::MoonTimeline>(shriek_entity->fields.EpilogueTimeline, "Resolve", 0);
diff --git a/projects/Randomizer/ui/main_menu_seed_info.cpp b/projects/Randomizer/ui/main_menu_seed_info.cpp
index 33c1909cd3f..6b5d77244ef 100644
--- a/projects/Randomizer/ui/main_menu_seed_info.cpp
+++ b/projects/Randomizer/ui/main_menu_seed_info.cpp
@@ -9,28 +9,29 @@
 #include <Core/api/graphics/sprite.h>
 #include <Core/api/messages/text_style.h>
 #include <Core/api/scenes/scene_load.h>
+#include <Core/api/system/save_files.h>
+#include <Core/events/action.h>
 #include <Core/utils/misc.h>
 #include <Modloader/app/methods/CleverMenuItem.h>
+#include <Modloader/app/methods/CleverMenuItemSelectionManager.h>
+#include <Modloader/app/methods/GameController.h>
 #include <Modloader/app/methods/GameStateMachine.h>
+#include <Modloader/app/methods/Grdk/Wrapper.h>
 #include <Modloader/app/methods/MessageBox.h>
 #include <Modloader/app/methods/SaveGameController.h>
 #include <Modloader/app/methods/SaveSlotsManager.h>
 #include <Modloader/app/methods/SaveSlotsUI.h>
 #include <Modloader/app/methods/SetTitleScreenAction.h>
 #include <Modloader/app/methods/System/IO/File.h>
-#include <Modloader/app/methods/CleverMenuItemSelectionManager.h>
-#include <Modloader/app/methods/GameController.h>
-#include <Modloader/app/methods/Grdk/Wrapper.h>
 #include <Modloader/app/types/CleverMenuItem.h>
 #include <Modloader/app/types/GameStateMachine.h>
 #include <Modloader/app/types/MessageBox.h>
 #include <Modloader/app/types/XboxLiveIdentityUI.h>
 #include <Modloader/modloader.h>
+#include <Randomizer/game/spawning_and_preloading.h>
 #include <Randomizer/randomizer.h>
 #include <Randomizer/seed/legacy_parser/parser.h>
 #include <magic_enum.hpp>
-#include <Core/events/action.h>
-#include <Randomizer/game/spawning_and_preloading.h>
 
 using namespace utils;
 using namespace app::classes;
@@ -432,20 +433,9 @@ namespace randomizer::main_menu_seed_info {
             if (SaveSlotsManager::SaveFileExists(index)) {
                 on_seed_loaded_handle = nullptr;
 
-                const auto save_controller = core::api::game::save_controller();
-
-                app::Byte__Array* data;
-
-                if (Grdk::Wrapper::get_InitializedOk()) {  // Handle GRDK (Xbox live) saves
-                    data = Grdk::Wrapper::Load_1(index, -1);
-                } else {
-                    const auto save_info = SaveGameController::GetSaveFileInfo(save_controller, index, -1);
-                    data = System::IO::File::ReadAllBytes(save_info->fields.m_FullSaveFilePath);
-                }
-
                 auto seed_meta_data = std::make_shared<seed::SaveSlotSeedMetaData>();
                 const auto read_slots = core::save_meta::read_save_meta_slots_from_byte_array(
-                    data,
+                    core::api::save_files::get_byte_array(index, -1),
                     {
                         {SaveMetaSlot::SeedMetaData, seed_meta_data}
                     }