Hans Leidekker (@hans) commented about dlls/odbc32/proxyodbc.c:
} else if (input->win32_handle) {
ret = input->win32_funcs->SQLAllocHandle( HandleType, input->win32_handle, &output->win32_handle );
ret = allochandle_win32(input, HandleType, input->win32_handle, &output->win32_handle);
This is emulating a v3 function (SQLAllocHandle()) with v2 functions (SQLAllocEnv()/..). Is that what native does? Is your app calling SQLAllocHandle() or is it us? In the latter case we may just need to handle that differently.