That'd be a terrifying setup for me as a live player! I'm curious where you found low latency wireless headphones though.
Have a look at Loopback - very mature app now. I use this for doing live and studio routing, you set a live profile so that only your soft synths actually get an output and Music (and FaceTime, system, whatever) get sent to the musical equivalent of /dev/null. So an accidental press of "Play" has no effect (beyond perhaps catastrophic stuttering as Music.app opens.)
My laptop is disconnected at the moment so it's full of "missing device" notifications but this screenshot[1] will give you an idea. Profiles on the left, apps in the next column, routing to mixer channels (I have a multichannel interface) next and then "monitor devices" which can be multiplexed.