Should I loop steel wire around a ceramic insulator on an electric fence?

I agree, we just rebuilt a few miles of pasture fence and using a separate piece of wire to attach leaves you a lot more flexibility if you have problems as well as leaves the main line stronger. You can even pre-cut short lengths ahead of time so it goes fast. Years ago I remember we could even buy wire like that in a bag with small loops on each end for attaching barb wire. After you get the main wire stretched along the knobs just take the short wire against the bottom of the knob and simultaneously bend both ends up and around the main line on both sides wrapping the same direction.

You're better off running the wire straight and putting a separate loop of wire around the insulator. That way if the fence post shifts, the insulator will slide along the wire. If you loop the current-carrying wire around the insulator, it can't slide and the wire is more likely to break.