How it looks is unimportant. How it works is.
Further forward for unmagnified optics allows you to keep both eyes open and focus on the target. It opens up your field of view and helps you stay on target. It may alter the balance of the weapon slightly by shifting the weight forward, but that is no big deal.
Positioning of magnified optics is usually a function of eye relief or available mounting hardware. Put it where you can see it, and or where you can see it properly with a good consistent cheek weld.
I have never met an instructor that advocates moving the optic back. But the important thing is that you actually try it out, and practice a lot. Then use what really works for you. It may or may not be what looks good or cool, but function is more important then appearance.