Wouldnt really do a thing. People's perspectives on what is broken and what is working correctly will always differ between each other. The feedback SE would get from these patch testers would be horrible, conflicting and completely biased.
None of the players will look at facts, only at what they would want for their own jobs, or what they wouldnt want other jobs to have. Lets face it, SE cant please everyone. Someone will always be fed up with something.
For example. Give something to DD job A, and DD job B will think it's overpowered because the thing they got was not up to par with it. Despite job A having a long history of not being played because players deem it too weak, and job B being the one that was completely overpowered originally. The same can be said about rivalling jobs. SCH getting things belonging to RDM, BLM or WHM. NIN's enternal struggle with PLD. Or just nagging about who is the best DD and why.
Despite (in my own opinion) all of the jobs are fairly balanced and equal now. Which, as some of you might not agree with that, would only prove my point that much more. Unless we would ever get one single stance on something, nothing would ever be helpful to be reported to SE. Just look around you here on the FFXI feedback forum, surely you have an opinion different from a lot of people there.