I see that the MSC-400 has a IR input which it blasts
out on all ports. Is there any way to do any routing with
the IR at all, like some of the Xantech IR routers?

The RT8 for example has one IR in, and you can control
which port to send the output to. One negative with this
is that the programming is involved since a route has
to be established per IR command and there is no concept
of device level routes.

Perhaps another way to ask the question - how do you make
the MSC-400 work with IR only remotes? Do they have pure
IR Triggers?