@ShinyHeadMusic
PAFL is for listening/checking audio, so pressing the PAFL key on any channel (input channel/mixes/FX) will only affect what is being sent to the PAFL bus.
The PAFL bus is sent to headphones, can be patched to an output directly and also feeds the ‘listen’ bus (which is like PAFL but with level control and mono/stereo outputs for use with IEM’s or a wedge).
So no, pressing the PAFL key on the master channel strip will not change the mix outputs in any way.
Cheers!
Keith.