I use two different length strings, if I have 2 leash plugs.
With only one leash plug:
I like a very thick leash string, so that it fills the plug and spreads the load to BOTH side of the bar.
When a leash string pulls hard on only ONE side of the bar, it can pull the bar out of the leash plug, during a nasty wipeout.
A bit hard to install a thick string... but worth it IMO.
Too many big fish, to be swimming at my breaks