Hi Zombielinux, The MST Hub is DP++ so it only requires passive adapters with an exception of using active adapters when you pass 1920×1200 resolution. In your case 1200×1920 in portrait mode is fine using passive adapters.
You can read more about the MST Hubs in our technology section.
I will be making more pages shortly so we can make more clear these questions. You can find the page here Welcome to Insights!