Live not communicating with controllers when in background

[MattGarland]

I'm running OSX Sierra with Live 9
I use a Push controller and a Novation Remote SL MK2
The MK2 is using Automap with a custom template that I've created with fixed mappings for the faders.

When performing, I run some real-time visuals software that Live communicates with via MIDI messages.
Ideally, I need to run the visuals software full-screen - as I don't want to project the window with ugly menu bar at the top. This visuals are projected.

However, if I have the software running full-screen, after a minute or so, Push will become unresponsive and the MK2 controls will too.
Audio continues to play through Live with no problem, and playing the keyboard on the MK2 still works.

Putting the visuals back into windowed mode and selecting the Live window restores things back to normal.

So it seems that this is a problem with Live and OSX - where Live running in the background causes problems.
I'd like to tell OSX not to de-prioritise background tasks.
I've tried some messing around with 'renice' in the terminal but it doesn't seem to change anything.

Any help would be greatly appreciated!!