diff --git a/src/spice2x/games/iidx/bi2x_hook.cpp b/src/spice2x/games/iidx/bi2x_hook.cpp
index 3755a1b..4c9dc81 100644
--- a/src/spice2x/games/iidx/bi2x_hook.cpp
+++ b/src/spice2x/games/iidx/bi2x_hook.cpp
@@ -1,5 +1,7 @@
 #include "bi2x_hook.h"
 
+#if SPICE64
+
 #include <cstdint>
 #include "util/detour.h"
 #include "util/logging.h"
@@ -24,17 +26,28 @@ namespace games::iidx {
         uint8_t data[0x10];
     };
 
-    struct AIO_NMGR_IOB2 {
-        uint8_t dummy0[0x50];
+    struct AIO_NMGR_IOB2_VTABLE {
+        // other functions here, but they never get called
+        uint8_t dummy[0x50];
         void (__fastcall *pAIO_NMGR_IOB_BeginManage)(int64_t a1);
-        uint8_t dummy1[0x9A0];
     };
 
+    struct AIO_NMGR_IOB2 {
+        AIO_NMGR_IOB2_VTABLE *vptr;
+        uint8_t dummy[0x9F0];
+    };
+
+    // confirmed 0x9F8 in iidx27, iidx32 aioNMgrIob2_Create
+    static_assert(sizeof(AIO_NMGR_IOB2) == 0x9F8);
+
     struct AIO_IOB2_BI2X_TDJ {
         // who knows
         uint8_t data[0x13F8];
     };
 
+    // confirmed 0x13F8 in iidx27, iidx32 in aioIob2Bi2xTDJ_Create
+    static_assert(sizeof(AIO_IOB2_BI2X_TDJ) == 0x13F8);
+
     struct AIO_IOB2_BI2X_TDJ__DEVSTATUS {
         // of course you could work with variables here
         uint8_t buffer[0xCA];
@@ -78,7 +91,7 @@ namespace games::iidx {
     // libaio-iob.dll
     typedef AC_HNDLIF* (__fastcall *aioIob2Bi2x_OpenSciUsbCdc_t)(uint8_t device_num);
     typedef int64_t (__fastcall *aioIob2Bi2x_WriteFirmGetState_t)(int64_t a1);
-    typedef AIO_NMGR_IOB2** (__fastcall *aioNMgrIob2_Create_t)(AC_HNDLIF *a1, unsigned int a2);
+    typedef AIO_NMGR_IOB2* (__fastcall *aioNMgrIob2_Create_t)(AC_HNDLIF *a1, unsigned int a2);
 
     /*
      * function pointers
@@ -443,7 +456,7 @@ namespace games::iidx {
         }
     }
 
-    static AC_HNDLIF* __fastcall aioIob2Bi2X_OpenSciUsbCdc(uint8_t device_num) {
+    static AC_HNDLIF* __fastcall aioIob2Bi2x_OpenSciUsbCdc(uint8_t device_num) {
         if (acHndlif == nullptr) {
             acHndlif = new AC_HNDLIF;
             memset(acHndlif->data, 0x0, sizeof(acHndlif->data));
@@ -456,14 +469,16 @@ namespace games::iidx {
         log_info("bi2x_hook", "AIO_NMGR_IOB::BeginManage");
     };
 
-    static AIO_NMGR_IOB2** __fastcall aioNMgrIob2_Create(AC_HNDLIF *a1, unsigned int a2) {
+    static AIO_NMGR_IOB2* __fastcall aioNMgrIob2_Create(AC_HNDLIF *a1, unsigned int a2) {
         if (aioNmgrIob2 == nullptr) {
-            aioNmgrIob2 = new AIO_NMGR_IOB2;
-            memset(aioNmgrIob2, 0x0, sizeof(AIO_NMGR_IOB2));
-            aioNmgrIob2->pAIO_NMGR_IOB_BeginManage = AIO_NMGR_IOB_BeginManageStub;
+            aioNmgrIob2 = new AIO_NMGR_IOB2{};
+            aioNmgrIob2->vptr = new AIO_NMGR_IOB2_VTABLE{};
+            aioNmgrIob2->vptr->pAIO_NMGR_IOB_BeginManage = AIO_NMGR_IOB_BeginManageStub;
         }
-        log_info("bi2x_hook", "aioNMgrIob2_Create");
-        return &aioNmgrIob2;
+        log_info("bi2x_hook", "aioNMgrIob2_Create returned {}, size=0x{:x}, vptr @ {}",
+            fmt::ptr(aioNmgrIob2), sizeof(*aioNmgrIob2), fmt::ptr(aioNmgrIob2->vptr));
+
+        return aioNmgrIob2;
     }
 
     static int64_t __fastcall aioIob2Bi2x_WriteFirmGetState(int64_t a1) {
@@ -520,10 +535,12 @@ namespace games::iidx {
         // hook IOB
         const auto libaioIobDll = "libaio-iob.dll";
         detour::trampoline_try(libaioIobDll, "aioIob2Bi2x_OpenSciUsbCdc",
-                aioIob2Bi2X_OpenSciUsbCdc, &aioIob2Bi2x_OpenSciUsbCdc_orig);
+                aioIob2Bi2x_OpenSciUsbCdc, &aioIob2Bi2x_OpenSciUsbCdc_orig);
         detour::trampoline_try(libaioIobDll, "aioIob2Bi2x_WriteFirmGetState",
                 aioIob2Bi2x_WriteFirmGetState, &aioIob2Bi2x_WriteFirmGetState_orig);
         detour::trampoline_try(libaioIobDll, "aioNMgrIob2_Create",
                 aioNMgrIob2_Create, &aioNMgrIob2_Create_orig);
     }
 }
+
+#endif
diff --git a/src/spice2x/games/iidx/bi2x_hook.h b/src/spice2x/games/iidx/bi2x_hook.h
index 6336fe5..af428ce 100644
--- a/src/spice2x/games/iidx/bi2x_hook.h
+++ b/src/spice2x/games/iidx/bi2x_hook.h
@@ -1,6 +1,10 @@
 #pragma once
 
+#if SPICE64
+
 namespace games::iidx {
 
     void bi2x_hook_init();
 }
+
+#endif
diff --git a/src/spice2x/games/iidx/iidx.cpp b/src/spice2x/games/iidx/iidx.cpp
index 2376485..967c6dc 100644
--- a/src/spice2x/games/iidx/iidx.cpp
+++ b/src/spice2x/games/iidx/iidx.cpp
@@ -251,6 +251,8 @@ namespace games::iidx {
         }
     }
 
+#if SPICE64
+
     typedef void* (*aioIob2Bi2x_CreateWriteFirmContext_t)(unsigned int, int);
     static aioIob2Bi2x_CreateWriteFirmContext_t aioIob2Bi2x_CreateWriteFirmContext_orig = nullptr;
 
@@ -269,6 +271,8 @@ namespace games::iidx {
         return nullptr;
     }
 
+#endif
+
     IIDXGame::IIDXGame() : Game("Beatmania IIDX") {
         logger::hook_add(log_hook, this);
     }
@@ -319,6 +323,8 @@ namespace games::iidx {
             devicehook_add(new IIDXFMSerialHandle());
         }
 
+#if SPICE64
+
         // check for new I/O DLL
         auto aio = libutils::try_library("libaio.dll");
         if (aio != nullptr) {
@@ -384,6 +390,8 @@ namespace games::iidx {
             }
         }
 
+#endif
+
         if (hooks::audio::ENABLED) {
             apply_audio_hacks();
         } else {
diff --git a/src/spice2x/games/sdvx/bi2x_hook.cpp b/src/spice2x/games/sdvx/bi2x_hook.cpp
index 50d8601..38f8a1c 100644
--- a/src/spice2x/games/sdvx/bi2x_hook.cpp
+++ b/src/spice2x/games/sdvx/bi2x_hook.cpp
@@ -1,5 +1,7 @@
 #include "bi2x_hook.h"
 
+#if SPICE64
+
 #include <cstdint>
 #include "util/detour.h"
 #include "util/logging.h"
@@ -15,7 +17,6 @@
 
 namespace games::sdvx {
     constexpr bool BI2X_PASSTHROUGH = false;
-    bool BI2X_INITIALIZED = false;
 
     /*
      * class definitions
@@ -26,17 +27,28 @@ namespace games::sdvx {
         uint8_t data[0x10];
     };
 
-    struct AIO_NMGR_IOB2 {
-        uint8_t dummy0[0x50];
+    struct AIO_NMGR_IOB2_VTABLE {
+        // other functions here, but they never get called
+        uint8_t dummy[0x50];
         void (__fastcall *pAIO_NMGR_IOB_BeginManage)(int64_t a1);
-        uint8_t dummy1[0x9A0];
     };
 
+    struct AIO_NMGR_IOB2 {
+        AIO_NMGR_IOB2_VTABLE *vptr;
+        uint8_t dummy[0x9F0];
+    };
+
+    // confirmed in EG final in aioNMgrIob2_Create
+    static_assert(sizeof(AIO_NMGR_IOB2) == 0x9F8);
+
     struct AIO_IOB2_BI2X_UFC {
         // who knows
-        uint8_t data[0x13F8];
+        uint8_t data[0x39D8];
     };
 
+    // confirmed in EG final in aioIob2Bi2xUFC_Create
+    static_assert(sizeof(AIO_IOB2_BI2X_UFC) == 0x39D8);
+
     struct AIO_IOB2_BI2X_UFC__DEVSTATUS {
         // of course you could work with variables here
         uint8_t buffer[0x19E];
@@ -66,7 +78,7 @@ namespace games::sdvx {
     // libaio-iob.dll
     typedef AC_HNDLIF* (__fastcall *aioIob2Bi2x_OpenSciUsbCdc_t)(uint8_t device_num);
     typedef int64_t (__fastcall *aioIob2Bi2x_WriteFirmGetState_t)(int64_t a1);
-    typedef AIO_NMGR_IOB2** (__fastcall *aioNMgrIob2_Create_t)(AC_HNDLIF *a1, unsigned int a2);
+    typedef AIO_NMGR_IOB2* (__fastcall *aioNMgrIob2_Create_t)(AC_HNDLIF *a1, unsigned int a2);
 
     /*
      * function pointers
@@ -345,21 +357,21 @@ namespace games::sdvx {
         log_info("bi2x_hook", "AIO_NMGR_IOB::BeginManage");
     }
 
-    static AIO_NMGR_IOB2** __fastcall aioNMgrIob2_Create(AC_HNDLIF *a1, unsigned int a2) {
+    static AIO_NMGR_IOB2* __fastcall aioNMgrIob2_Create(AC_HNDLIF *a1, unsigned int a2) {
         if (aioNmgrIob2 == nullptr) {
-            aioNmgrIob2 = new AIO_NMGR_IOB2;
-            memset(aioNmgrIob2, 0x0, sizeof(AIO_NMGR_IOB2));
-            aioNmgrIob2->pAIO_NMGR_IOB_BeginManage = AIO_NMGR_IOB_BeginManageStub;
+            aioNmgrIob2 = new AIO_NMGR_IOB2{};
+            aioNmgrIob2->vptr = new AIO_NMGR_IOB2_VTABLE{};
+            aioNmgrIob2->vptr->pAIO_NMGR_IOB_BeginManage = AIO_NMGR_IOB_BeginManageStub;
         }
-        log_info("bi2x_hook", "aioNMgrIob2_Create");
-        BI2X_INITIALIZED = true;
+        log_info("bi2x_hook", "aioNMgrIob2_Create returned {}, size=0x{:x}, vptr @ {}",
+            fmt::ptr(aioNmgrIob2), sizeof(*aioNmgrIob2), fmt::ptr(aioNmgrIob2->vptr));
 
         // enable hack to make PIN pad work for KFC in BI2X mode
         // this explicit check in the I/O init path is necessary
         // (as opposed to just doing a check for "isValkyrieCabMode?")
         // because there are hex edits that allow you to use legacy (KFC/BIO2) IO while in Valk mode
         acioemu::ICCA_DEVICE_HACK = true;
-        return &aioNmgrIob2;
+        return aioNmgrIob2;
     }
 
     static int64_t __fastcall aioIob2Bi2x_WriteFirmGetState(int64_t a1) {
@@ -411,3 +423,5 @@ namespace games::sdvx {
                 aioNMgrIob2_Create, &aioNMgrIob2_Create_orig);
     }
 }
+
+#endif
\ No newline at end of file
diff --git a/src/spice2x/games/sdvx/bi2x_hook.h b/src/spice2x/games/sdvx/bi2x_hook.h
index fb29d1b..bdf1d4b 100644
--- a/src/spice2x/games/sdvx/bi2x_hook.h
+++ b/src/spice2x/games/sdvx/bi2x_hook.h
@@ -1,6 +1,10 @@
 #pragma once
 
+#if SPICE64
+
 namespace games::sdvx {
 
     void bi2x_hook_init();
 }
+
+#endif
\ No newline at end of file
diff --git a/src/spice2x/games/sdvx/sdvx.h b/src/spice2x/games/sdvx/sdvx.h
index e6fa328..f2ae34a 100644
--- a/src/spice2x/games/sdvx/sdvx.h
+++ b/src/spice2x/games/sdvx/sdvx.h
@@ -20,7 +20,6 @@ namespace games::sdvx {
     extern bool NATIVETOUCH;
     extern uint8_t DIGITAL_KNOB_SENS;
     extern std::optional<std::string> ASIO_DRIVER;
-    extern bool BI2X_INITIALIZED;
     extern SdvxOverlayPosition OVERLAY_POS;
 
     // states