I did find another MSC-400 issue however.

Any time you trigger a Smart Macro on the MSC-400 from the MX-980, an IR burst goes out to *ALL* attached IR emitters, regardless of your port settings on the MSC-400 or MX-980.

The IR burst is short and is not the full sequence being processed in the smart macro. I've tested it with a repeating sequence and it doesn't continue to blast IR to all ports.

What I haven't done yet is connect a learner to one of the emitters to capture what is being blasted.