TODO: try portable D3DX9_43.dll

[BinToss]

When installed/registered and then copied into SPV3's game directory, OpenSauce will prefer loading ./D3DX9_43.dll over %WINDOWS%/SysWow6432/D3DX9_43.dll.

What if we don't install and register the module?

This will require setting up a clean VM that does not have D3DX 9 (nor the entire DirectX eXtensions package) installed and registered.
If Windows Sandbox is used, verify it does not copy the host system directories.