multiple constant drivers for net IOP_

I aggree, that buffer can and should be avoided. The problem however isn't due to the buffer port type rather than the fact, that's an output (as any buffer).

To add my strongest personal dislikings in the present post: Positional association with component instantiation. And - unneccessary long example code, that could be easily reduced, which would be also the first step to locate the coding error by yourself.