Mackie controller

[Glitchless]

I just upgraded my computer and moved to the RME Fireface 800 from the Yamaha DSP 2416 cards. The Fireface on screen matrix interface has taken me a bit of work to figure out. My main problem with it is not being able to make any adjustment on the fly without Nuendo stopping whatever process it was doing.
With the Yamaha cards the two mixers were integrated in the program and could be accessed and used on the fly.
I think I can control both from my Mackie controller, but I've yet to figure out how. It appears random whether I will see the names of the tracks from the VST mixer or the Fireface inputs or outputs. I have figured out how to flip from one to the other.
Any wisdom out there?