There is no i686 DXVK package. No i386 alternatives for DLLs.
$ update-alternatives --list | grep -E 'wine-(d3|dx)'
wine-d3d10(x86-64) auto /usr/lib64/wine/x86_64-windows/wine-d3d10.dll
wine-dxgi(x86-64) auto /usr/lib64/wine/x86_64-windows/dxvk-dxgi.dll
wine-d3d8(x86-32) auto /usr/lib/wine/i386-windows/wine-d3d8.dll
wine-d3d11(x86-32) auto /usr/lib/wine/i386-windows/wine-d3d11.dll
wine-d3d10(x86-32) auto /usr/lib/wine/i386-windows/wine-d3d10.dll
wine-d3d8(x86-64) auto /usr/lib64/wine/x86_64-windows/dxvk-d3d8.dll
wine-d3d10core(x86-64) auto /usr/lib64/wine/x86_64-windows/dxvk-d3d10core.dll
wine-d3d9(x86-64) auto /usr/lib64/wine/x86_64-windows/dxvk-d3d9.dll
wine-d3d10core(x86-32) auto /usr/lib/wine/i386-windows/wine-d3d10core.dll
wine-d3d9(x86-32) auto /usr/lib/wine/i386-windows/wine-d3d9.dll
wine-d3d11(x86-64) auto /usr/lib64/wine/x86_64-windows/dxvk-d3d11.dll
wine-dxgi(x86-32) auto /usr/lib/wine/i386-windows/wine-dxgi.dll
32-bit application inside newly created prefix doesn’t pick up 64-bit DXVK libraries and uses WineD3D despite native DLL overrides.
Putting 32-bit DLLs from the official DXVK release archive into $WINEPREFIX/drive_c/windows/syswow64 solves the problem.
WineD3D/DXVK usage can be confirmed with mangohud.