The first one I set up I edited it first the next four rigs I built I did it after. You might lose out on five minutes of mining. I burn the USB and stick it straight in the rig and turn it on. Once it is up and running I edit the 1bash (which is much easier in Linux with the highlighting) and then save it and reboot.

I had an issue one time with a bad usb image. Not sure what happened but making sure it boots with the default setup before taking the time to edit the 1bash seems like a good time saving idea to me.

The only downside is you may not have your payment addresses where you can access them on the new Linux boot up. I HATE manually typing them out and always prefer to copy and paste. With multiple rigs I just SSH to another rig and copy and paste from one 1bash to another.