https://bugs.winehq.org/show_bug.cgi?id=36960
--- Comment #5 from Gijs Vermeulen gijsvrm@gmail.com --- This bug is gone with wine-5.17. The game now chokes on d3dx9_mesh_OptimizeInplace returning E_NOTIMPL when D3DXMESHOPT_ATTRSORT is passed and `(flags & (D3DXMESHOPT_COMPACT | D3DXMESHOPT_IGNOREVERTS | D3DXMESHOPT_ATTRSORT)) == D3DXMESHOPT_COMPACT` is false. Commenting out this check makes the game work fully for me, without noticeable visual glitches.
Matteo, is getting rid of this check an absolute no-go?