I use an 8in 8out usb midi interface for my computer. Then I can send legacy midi around however I need with a lot less problem.
Like I was using all these usb ports and that gets messy in xp.
I have a few different older midi interfaces that work as a merger.
Like a motu 4in 6out unit that will echo any input to every output except the like number output. So if you plug into input 3 it will come out every output port except 3.
The motu stuff is good about stuff like that, has several preset functions built in.
If a bigger interface from the computer would do what you want I'd go with that.