I have a suggestion for Spiral Knights PvP: Fair Play.
Suggestion is simple as hell: don't put players with little lag and high lag into same room when playing PvP.
Reasoning is very simple: those with small ping times have an upper hand (advantage) over players with large (long) ping times. Which can be classified as a cheat.
Simple example:
with my lag if I stop anywhere, a player runs up to me, puts two bombs on my sides and runs away before I can move. And I am left standing between 2 walls and 2 bombs, unable to move. No, to be precise: I am teleported 3 tiles backwards and locked between 2 bombs and 2 walls.

Another simple example:
I see a player planting a bomb, and then almost immediately I am blown away by that bomb, 1-2 seconds before it should blow up. Reason behind it: bomb was planted a long time ago but my ping only showed it now. Afterwards the bomb exploded and explosion hit be (because I didn't move away because I didn't know it was planted a long time ago).
Basically, you can call that instabomb. Someone plants a bomb and it blows up almost immediately.

My idea is simple: those with small ping times should only play with other players who have small ping times.
Those with high ping times should play with those who also have high ping times.
Grouping players can be done this way:
below 150ms - group "low lag"
above 150 and below 300 ms - "medium lag"
above 300 and below 500 ms - "high lag"

Anyone with ping above 500 ms should be warned their game will be unplayable.