So I think we can safety agree no one really cares about Proving Grounds ranking. Heck, I only did it for the awesome title I wear. But I did have a quick idea I had as an improvement to the Proving Grounds that could help find better quality pug DPS:
-Like the proving grounds you queue up, zone in alone, and find a single target dummy in the center of the room.
-Flask, potions, food, and consumables are provided for you, but only last while in the instance. No other consumables allowed.
-Timer counts down to begin and players attacks the target dummy for a specific amount of predetermined time (1 - 2 mins or so) with everything they've got.
-Abilities that need to be interrupted and fire that needs to be avoided are also present, so players can't just stare at their action bars the entire time. Mostly to check if they can acknowledge that their interrupt is a thing that exists and is on their bars.
-No heroism/bloodlust allowed.
-Players can attempt this as many times as they want.
-Item levels could even be scaled so everyone is on an even playing field in terms of gear.
After their time is up the game calculates the player's DPS for the attempt. Their highest score on record is displayed next to a player's item level whenever they are queueing for a DPS spot in LFG.
Of course, this idea is mainly aimed towards players that actually pug and want to improve their chances at getting picked, so people who stick to guild & friend groups don't have to worry about this. Though it could be a fun competition between players to see who could rank the highest. It's basically a more simple raider.io score except you can't be carried through it (like buying heroic runs), you and only you have better control over how high or low it is, and it isn't controlled by a 3rd party website. Something that'll help you avoid players that get out dpsed by the healers. I know there's no chance Blizzard would actually put something like this in game, seeing as they wouldn't want to disenfranchise their lower skilled player base, but I'm still curious to see what others think about this.