I'm going to have to agree with the OP partially on this.
Many of the features of the clients ARE game breaking.
Turning off darkness, You character isn't meant to be able to see in the dark, and you should not be able to mine and fight in pitch black. Further viewing range is a blatant advantage you can't do with default client, it lets you do things like shoot from further away which you just can't do normally.
NOW on the other hand some things SHOULD be in the default client. Like Being able to look behind trees and rocks? That makes perfect sense, the character should be able to do that.
Will Jorb and Loftar do anything about it? I would estimate a 0.3 % chance.