(I don't know if this has already been suggested; I'm not active on forums.)
As you may or may not know, if u jump into PvP from the /warp pvp platform, you get a 10 second invincibility. Now I don't really know why this was implemented, but it seems kinda pointless in my opinion.
After dying, people can jump straight back in, pick up there loot if some is still left on the floor and run out without having any worries about being killed. And yes, you can easily jump in, run to and up the ladder (because the ladders are too short.. but das a different suggestion xD) in under 10 seconds, ive tested it.
Also, if there are people down in PvP, by the time the invincibility wheres off they have already run out and won't be coming in for the remaining time that you are online.
Some may say 'but what if I accidentally fall in'. There is a barrier stopping you, and also 4 warning signs saying PvP below. If you still 'accidentally' full in I honestly don't know whats wrong.
So please, remove the invincibility.