diff --git a/rpcs3/Emu/Cell/lv2/sys_sync.h b/rpcs3/Emu/Cell/lv2/sys_sync.h
index 0d6162e664..98df7cd729 100644
--- a/rpcs3/Emu/Cell/lv2/sys_sync.h
+++ b/rpcs3/Emu/Cell/lv2/sys_sync.h
@@ -84,6 +84,11 @@ private:
 public:
 	SAVESTATE_INIT_POS(4); // Dependency on PPUs
 
+	lv2_obj() noexcept = default;
+	lv2_obj(u32 i) noexcept : exists{ i } {}
+	lv2_obj(utils::serial&) noexcept {}
+	void save(utils::serial&) {}
+
 	// Existence validation (workaround for shared-ptr ref-counting)
 	atomic_t<u32> exists = 0;
 
diff --git a/rpcs3/Emu/IdManager.h b/rpcs3/Emu/IdManager.h
index 4c98a35e43..b75cb73e47 100644
--- a/rpcs3/Emu/IdManager.h
+++ b/rpcs3/Emu/IdManager.h
@@ -248,16 +248,17 @@ namespace id_manager
 		std::vector<std::pair<id_key, std::shared_ptr<void>>> vec{}, private_copy{};
 		shared_mutex mutex{}; // TODO: Use this instead of global mutex
 
-		id_map()
+		id_map() noexcept
 		{
 			// Preallocate memory
 			vec.reserve(T::id_count);
 		}
 
 		// Order it directly before the source type's position
-		static constexpr double savestate_init_pos = std::bit_cast<double>(std::bit_cast<u64>(T::savestate_init_pos) - 1);
+		static constexpr double savestate_init_pos_original = T::savestate_init_pos;
+		static constexpr double savestate_init_pos = std::bit_cast<double>(std::bit_cast<u64>(savestate_init_pos_original) - 1);
 
-		id_map(utils::serial& ar)
+		id_map(utils::serial& ar) noexcept requires (savestate_init_pos_original != 0 && std::is_constructible_v<T, stx::exact_t<utils::serial&>>)
 		{
 			vec.resize(T::id_count);
 
@@ -297,7 +298,7 @@ namespace id_manager
 			}
 		}
 
-		void save(utils::serial& ar)
+		void save(utils::serial& ar) requires (savestate_init_pos_original != 0 && std::is_constructible_v<T, stx::exact_t<utils::serial&>>)
 		{
 			u32 obj_count = 0;
 			usz obj_count_offs = ar.data.size();
@@ -334,8 +335,7 @@ namespace id_manager
 			std::memcpy(ar.data.data() + obj_count_offs, &obj_count, sizeof(obj_count));
 		}
 
-		template <bool dummy = false> requires (std::is_assignable_v<T&, thread_state>)
-		id_map& operator=(thread_state state)
+		id_map& operator=(thread_state state) noexcept requires (std::is_assignable_v<T&, thread_state>)
 		{
 			if (private_copy.empty())
 			{
diff --git a/rpcs3/util/types.hpp b/rpcs3/util/types.hpp
index fb44d45bdb..23e617e2d9 100644
--- a/rpcs3/util/types.hpp
+++ b/rpcs3/util/types.hpp
@@ -1353,4 +1353,4 @@ extern bool serialize(utils::serial& ar, T& obj);
 }()
 
 #define ENABLE_BITWISE_SERIALIZATION using enable_bitcopy = std::true_type;
-#define SAVESTATE_INIT_POS(x) static constexpr double savestate_init_pos = (x)
+#define SAVESTATE_INIT_POS(...) static constexpr double savestate_init_pos = (__VA_ARGS__)