Black Magic Ultrastudio 4K TB2

[kiwi]

Also it's just one input into the Mac, the different inputs on the Aja can be switched by the software

Am I correct in thinking this is 4 inputs into the box but only one input into Catalyst? rather than 4 simultaneous inputs into Cat?
Guessing the switching you refer to is done in the AJA software? or can you use something like 232 from Cat to switch the inputs on the box?