Thank you for telling us that. Not sure if it's a good thing though. Gain and volume are understandable, but EQ isn't used only to fix the cans' FR: sometimes it's for bad recording. Or just pure fun. And balance can be useful for people with bad hearing. Not every DAC or amp would allow changing balance.
Oh well. Not that I personally EQ much IRL :)
Consider this: Line-out (and digital-out) is so that you get the purest and cleanest output from the source. The second you start to mix in all the extra stuffs, you lose the first and foremost important thing - an untainted signal of the highest quality. What is the point of a line-out if it is not even an actual line-level signal in the first place and doesn't offer any difference from the headphone-out? Wouldn't it be easier just to double amp the headphone-out that way? That's why you either get a line-out, or you are not going to get a line-out at all.
That being said, I don't see line-out being used much on the X3 because of how capable the amp section is.