Whenever I've been playing in the PVP arena, I've noticed that a lot of the time people will camp the entrance with Knockback words or Punch bows, then they only need to hit you once and you fall in the lava and die.
I think this is a problem because some people seem to use it as a tactic which is a very unfair advantage. My suggestion would be to change it to a ring of fire, or just remove the lava from right in front of the entrances. Hopefully this idea will be supported because i think it'd make for a more fair fight.