In case anyone’s interested, I’ve been having problems on my MacPro (cylinder), where the best I could achieve from A4 and Rytm, was a stereo pair each.
Having upgraded to MacOS Sierra, I can now run 6 channels each! I had to use the work-around described in the “Overbridge in macOS Sierra” topic, but the difference is wonderful!
Note - Sierra isn’t yet supported and you’ll be taking a risk, but it holds out promise of a much better system for some of us, when Elektron release new drivers. 
I realize that you haven’t had much time to ‘play’ with this setup yet but interested to know which DAW you are using? Have you been able to try Logic Pro - does the new Sierra OS improve OB in Logic?
I dont mind using Ableton but I’ve invested years in Logic and its just another learning curve to move to Ableton just so that i can make the most of my Elektrons in a DAW setup?
Thx for your investigation into this. Its good to know that we can get OB working in Sierra.
Cubase and Ableton (latest versions) are what I use. I’d expect if they work, Logic should hypothetically be OK…?