So I don't have a PC cable to check for myself, but does anyone know if a 600 or similar set as master, will act as master as per normal (i.e. firing all the slaves) if it (the master) is triggered through its PC port?
The PC port is 'dumb' – it sends only the signal to fire (you need to set power manually). If you want to use the 600 as a master, you need to connect it to the hotshoe, directly or via an E-TTL extension cord (Canon OC-E3 or a longer 3rd party variant, check flashzebra.com).
So I don't have a PC cable to check for myself, but does anyone know if a 600 or similar set as master, will act as master as per normal (i.e. firing all the slaves) if it (the master) is triggered through its PC port?